Democratic Republic of Congo, a vast country in the heart of Africa, is trying to find its feet on the path to peace after a five-year conflict dubbed "Africa's world war" that involved seven countries and enveloped the region.

The country's first post-war elections were held in 2006, but the vote highlighted a deep east-west divide along ethnic and linguistic lines. Furthermore, many observers say ongoing violence in more remote areas could destabilise the peace process and re-ignite the regional war that officially ended in 2003.

The largest U.N. peacekeeping force in the world is stationed in Congo, with 17,000 troops, and the International Criminal Court in The Hague has launched investigations into war crimes.

But it's a Herculean task keeping control of a country the size of western Europe and lacking the most basic infrastructure. Jungle paths or rivers are often the only routes of transit in the country formerly renamed Zaire.

Dozens of heavily armed groups - some of them still reportedly backed by influential politicians or foreign governments such as Rwanda and Uganda - stoke ethnic rivalries and vie for control of valuable natural resources.

Rwanda and Uganda officially withdrew their troops from Congo in 2002 and 2003, and although they are often accused of keeping a foothold in Congo through proxy militias, much of the violence in the northeastern border regions originates in the power vacuum left behind when their armies pulled out.

Militias regularly target civilian men, women and children, while brutal rapes are common and thousands of families are on the run for their lives.

Some 5.4 million people have died since 1998 from violence and war-related illness, according to studies by U.S.-based aid agency International Rescue Committee, which says fighting frequently prevents people from seeking out what scant health services are available.

"Congo is the deadliest conflict anywhere in the world over the past 60 years," said Richard Brennan, IRC's health director.

More than 370,000 Congolese refugees are scattered across the region, although some have returned home, says the U.N. refugee agency, UNHCR.

Almost 1.4 million people are displaced within the country's borders, according to the Internal Displacement Monitoring Centre, and waves of violence means many more are regularly uprooted from homes for short periods of time. In May 2009, some 1.8 million were displaced in North Kivu alone - 75 percent of them living with host families, according to the United Nations.

Aid experts regularly cite the crisis in Congo as the most underreported emergency in the world.

RAPE

The actual number of women and girls raped in eastern Congo is unknown, but experts and campaigners say the scale is enormous.

Forty women are raped every day, according to the Congolese Women's Campaign Against Sexual Violence in the Democratic Republic of Congo. And the United Nations said 26,000 women had been raped in South Kivu alone in 2006, although the number of reported cases had dropped to 463 in the first quarter of 2009.

It is not just the sheer numbers but also the form the rape takes. "To see so many raped, that shocks me, but what shocks me more is the way they are raped," says Denis Mukwege an award-winning Congolese doctor who established Panzi Hospital of Bukavu in South Kivu, which treats women for their injuries.

Militia groups and soldiers target all ages - including girls as young as three and elderly women. They are gang raped, raped with bayonets, and have guns shot into their vaginas, destroying their reproductive and digestive systems. Men and boys have also been raped.

The rape epidemic began in the mid-1990s, according to Wilhelmine Ntakebuka, who coordinates a sexual violence program in Bukavu. This is when Rwandan Hutu militiamen escaped to Congo after taking part in Rwanda's genocide.

"We don't know why these rapes are happening, but one thing is clear - they are done to destroy women," says Mukwege.

In some cases armed men brutalise villagers for food and loot, in others they use rape as a weapon of war either to force locals to accept the power and authorities of a particular armed group. It can destroy entire communities.

Rape traumatises girls and women, humiliates their husbands and can break up families. Women become fearful of working in the fields and taking goods to sell at market, reducing family incomes. If they have been badly injured they may not be able to have more children. Many who are raped are divorced by their husbands and lose their home.

Local women's groups offer shelters in local towns and help survivors learn new skills, but their resources are limited. In some cases, survivors pool their resources and rent accommodation together.

Many Congolese women activists seeking to help survivors and highlight the issue internationally, themselves become targets and receive death threats. They and international aid agencies are urging for improved justice systems to deal with the perpetrators.

"The sexual violence in Congo is the worst in the world," says John Holmes, the United Nations under secretary general for humanitarian affairs. "The sheer numbers, the wholesale brutality, the culture of impunity - it's appalling."

From 1965 until 1997, the country was ruled with an iron fist by Mobutu Sese Seko (see end).

The origins of Congo's war, which began during his rule, are intimately connected to the 1994 genocide in neighbouring Rwanda, where some 800,000 people from the minority Tutsis and political moderates from the majority Hutus were slaughtered at the instigation of the extremist Hutu government.

Rwanda's post-war Tutsi government invaded Congo in 1996 to pursue extremist Hutu militias that had crossed the border, in the process helping Congolese rebels end Mobutu's 32-year rule.

Rwanda installed rebel leader Laurent Kabila as president but then turned against him when he started stirring hatred towards Tutsis in Congo. Rwanda intervened to try to remove Kabila, but he fought them off with assistance from Angola, Namibia and Zimbabwe, while Uganda weighed in on the Rwandan side.

The ensuing regional war raged from 1998 to 2003.

Joseph Kabila took power after the assassination of his father Laurent in January 2001, and began negotiating peace.

He set up a temporary power-sharing government with four vice-presidents, two of them from former rebel groups, and then won presidential elections in 2006.

Although Kabila is popular in the Swahili-speaking east of the country, he's viewed as an outsider by many people in Kinshasa and the west, where Lingala is the main language.

Kinshasa politicians, local bigwigs and neighbouring countries are accused of cashing in on valuable natural resources in eastern Congo, and international rights activists say Rwanda and Uganda continue to arm and fund militias in the area even after pulling out their national troops.

The 2006 elections, won by Kabila and his Alliance for the Presidential Majority, marked the first time in 40 years the country had freely gone to the ballot to vote for a leader.

The election year was marred by sporadic clashes between Kabila followers and supporters of his main rival, Jean-Pierre Bemba, who says he remains convinced the international community had Kabila lined up for the job already.

The government is hobbled by endemic corruption, and analysts say there's still the risk that politicians sidelined by elections could voice their opposition in street protests and violence rather than the political arena.

Congo's new army is meant to unite tens of thousands of former gunmen who fought with a plethora of armed groups, but soldiers are ill-disciplined, poorly fed and don't have proper equipment, according to Belgian-based think tank International Crisis Group.

Militia groups abduct children - often from schools - to fight or act as porters, spies and sex slaves. Hundreds have been released as armed groups integrate into the army. But British-based aid agency Save the Children estimated in February 2009 that more than 1,000 children were still trapped, and reported a surge in abductions in the north by the Ugandan rebel Lord's Resistance Army.

Human Rights Watch says child soldiers are often hidden from observers or coached to say they're over 18.

Army living conditions are appalling, without barracks or canteens, let alone health services, and experts say their salary is not a living wage. As a result, soldiers often resort to taxing and abusing the local population.

In the east of the country, government soldiers have fled their posts rather than fight against militias and villagers have reported being attacked by the national army as well as other gunmen.

The army is still the largest human rights abuser in the country, Crisis Group said in a 2009 report.

The United Nations sent a mission to Congo - MONUC - in 2000.

Peacekeepers have been dogged by accusations of sexual exploitation of women and children. They have also been accused of smuggling gold in exchange for guns.

A 38,000-strong national police force has been deployed around the country, but Crisis Group said it was concerned training focused too much on crowd control and not enough on ordinary policing skills such as criminal investigation, making statements, and procedures for dealing with sexual violence.

Although many former rebels have given up their guns or joined the national army, others are still resisting the integration process and continue to fight over resources, territory or ethnic grievances.

It is hard to keep up with the shifting loyalties of various armed groups operating in Congo and their leaders, some of whom have been backed at various times by Rwanda or Uganda but later switched sides. And sometimes rival militias join forces to take on the national army.

Then there are militias called Mai Mai, who model themselves on traditional warriors, touting talismans that they say make them invincible and terrorising villagers.

Fighting occasionally follows ethnic divisions, frequently stirred up by politicians both in Congo and outside, since some Congolese tribes have affinities with Hutus or Tutsis in neighbouring Rwanda and Burundi.

Rebels from northern Uganda have also caused trouble. The Lord's Resistance Army, which terrorised civilians in Uganda for two decades, has bases in northern Congo. In December 2008 Uganda's army, backed by Congolese and South Sudanese troops, launched a military offensive against the bases.

LRA fighters have responded by looting local villages, killing hundreds and displacing tens of thousands.

The International Criminal Court is prosecuting Congolese militia leader Thomas Lubanga, leader of the Union of Congolese Patriots, for war crimes. Lubanga was the first suspect to be delivered to the court.

The court has also issued an arrest warrant for one of Lubanga's subordinates, General Bosco Ntaganda, accused of recruiting children under 15 to fight in an ethnic-based conflict in northeast Ituri district in 2002 and 2003.

Ntaganda took control of eastern Congo's main Tutsi rebel group, the National Congress of the Defence of the People, in early 2009.

North Kivu and South Kivu

North Kivu was the epicentre of Congo's war, and rebel groups and militias continue to fight for land and resources in this remote eastern region.

The main rebel group is the Hutu-dominated Democratic Forces for the Liberation of Rwanda (FDLR), composed partly of Rwandan ex-soldiers and Interahamwe militia who fled to Congo after participating in the 1994 genocide in their home country. The FDLR are seen to be a root cause of the region's 15 years of conflict.

Congo and neighbouring Rwanda launched a joint military offensive in January 2009 against the rebel group. It was the most concerted pressure on the rebels for years. Rwandan troops withdrew a month later. FDLR fighters stepped up reprisals against villagers they accused of siding with their enemies, and retook ground they lost during the offensive. Tens of thousands fled their homes.

The military operation helped to neutralise another major rebel group, the North Kivu-based National Congress of the Defence of the People (CNDP). The CNDP was formed in July 2006 by self-styled general Laurent Nkunda, a former commander of the main rebel group that controlled the eastern part of the country during the Congolese war, the Rwandan-backed Congolese Rally for Democracy (RCD).

Nkunda's traditional enemy was the FDLR. A Tutsi born in North Kivu, Nkunda said he wanted to protect fellow Congolese who speak Kinyarwanda, a language of Rwandan origin. (The Rwandan-backed RCD initially united Hutus and Tutsis in North Kivu, where both tribes speak Kinyarwanda.)

He rejected conciliation with the government right through the 2006 election period, but started integrating his 4,000 well-trained troops into the national army in February 2007. Brigades consisting of army soldiers and his rebels were established to pursue the Hutu militias.

Not everyone thought the deal allowing Nkunda into the army was a good thing. The then U.N. Human Rights Commissioner Louise Arbour said it was a serious error. Rights groups accused the brigades of rape, arbitrary killings and systematic displacement of civilians.

By August 2007, the army had halted Tutsi-led operations against Rwandan Hutu rebels in a bid to avoid further ethnic tension, and Nkunda's forces renewed attacks on the government army. The U.N. negotiated a ceasefire in September, but it fell apart a month later and clashes resumed.

The government, Nkunda and several other rebel groups - but not the FDLR - signed a peace deal in January 2008, but by August this too had collapsed. Nkunda launched a fresh offensive on army bases and areas under the formal protection of U.N. peacekeepers.

Nkunda's rebellion peaked in late 2008 when he captured large swathes of territory and threatened North Kivu's regional capital Goma, forcing more than a quarter of a million people to flee their homes. The army abandoned positions near Goma and looted and raped civilians in and around the city. Intense international diplomatic pressure stopped Nkunda advancing further.

In January 2009, Nkunda was ousted by General Bosco Ntaganda who took command of the CNDP, which pledged to abandon its four-year insurgency, raising fresh hopes for peace.

Later that month, Nkunda was arrested in Rwanda on charges of war crimes. Some of these alleged crimes have been documented by New York-based Human Rights Watch which says his troops have carried out numerous killings, torture and rapes. See its October 2007 report.

Ntaganda has been indicted by the International Criminal Court for recruiting child soldiers to fight in Ituri province in 2002 and 2003. Despite this, he is playing a prominent role in the army's offensive against the FDLR according to Congolese army documents seen by Reuters in April 2009.

Congo and the U.N. peacekeeping mission plan to extend their anti-FDLR operations to South Kivu where the rebels earn most of their money from controlling mines and illegally taxing the population.

Ituri

The mineral-rich northeastern province of Ituri was basically under Ugandan control throughout the war. During their occupation, which ran from 1998 to May 2003, Ugandan soldiers provided arms and military training to different ethnic groups, fostering the spread of an initially limited land dispute between Hema and Lendu.

The Hema are pastoralists and the Lendu farmers, but the majority of Ituri's population are neither Hema nor Lendu, says Human Rights Watch. However, they were all forced to take sides, and became subject to attacks because of their perceived association with either Hema or Lendu groups.

During Congo's war, Uganda, Rwanda and Congolese governments all supported different militia groups in Ituri.

Just when Congo was forming a transitional government in 2003 and embarking on its peace process, Ituri was on the verge of genocide says the International Crisis Group.

The worst of the conflict raged for nearly a decade until a 2006 ceasefire led to a peace deal. Since then most armed groups have been dismantled and former rebels integrated into the army or demobilised, and the presence of U.N. peacekeepers has helped contain other outbreaks of violence.

But the process could still be reversed, say analysts.

Fighting between rival militias, the Congolese army and U.N. peacekeepers continues, displacing thousands. Militias still active in the area include the Popular Front for Justice in the Congo and the Revolutionary Front for Peace.

Tensions remain over access to land and natural resource revenues including from gold and timber. Some fear the presence of oil under Lake Albert, which lies between Ituri and Uganda, may spark further conflict.

And the return of thousands of displaced people, many of whose homes have been occupied in their absence, has also exacerbated ill-feeling.

There is little trust between the different communities, and abuses committed during the conflict have for the most part gone unpunished. Also, the Congolese army continues to perpetrate human rights abuses in Ituri.

Thomas Lubanga, leader of the ethnic Hema-dominated Union of Congolese Patriots (UPC) militia, was the first suspect to face trial at the International Criminal Court (ICC), accused of recruiting children during the UPC's occupation of the regional capital Bunia between August 2002 and March 2003.

Lubanga's deputy during the Ituri wars, Bosco Ntaganda, is also wanted by the ICC.

Two warlords from the other side of the Ituri conflict, Germain Katanga and Mathieu Ngudjolo, are accused by ICC prosecutors of war crimes and crimes against humanity including murder, sexual slavery, rape, inhumane acts and recruiting child soldiers.

Katanga, also known as "Simba", or lion, led the Patriotic Forces of Resistance of Ituri (FRPI), while Ngudjolo headed the allied Front of Nationalists and Integrationalists (FPI) militia.

Human Rights Watch tracked who was who in Ituri's armed groups in 2003.

Orientale

Lord's Resistance Army (LRA) rebels, who have terrorised northern Uganda for two decades, crossed into the northeastern province of Orientale during 2005.

Eight Guatemalan peacekeepers were killed in January 2006 when the United Nations launched a special operation to capture LRA Deputy Commander Vincent Otti. Otti, who was indicted for war crimes by the International Criminal Court, was killed by his own allies in late 2007.

In December 2008 Uganda launched a military offensive, backed by Congolese and South Sudanese troops, against the LRA bases in Orientale.

The LRA responded by attacking local villages, forcing tens of thousands to flee. They continue to terrorise the area.

Katanga

Violence in Congo's most mineral-rich province has eased, although there are still abuses carried out by both ex-government militias called Mai Mai and the local police and army, especially in the lawless and remote north of the province.

The flare-up of warfare in North Kivu in late 2008 and 2009 may have repercussions for Katanga. There have been reports of Mai Mai fighters regrouping in the centre of the province, says the Belgium-based International Peace Information Service (IPIS). There are also a limited number of fighters from the Hutu-dominated Democratic Forces for the Liberation of Rwanda (FDLR) in the north of the province.

And the global recession has had a huge impact on the province, as demand for its minerals plummeted. Local authorities estimated in March 2009 that 300,000 people had lost their jobs almost overnight.

The home province of President Kabila has a long history of unrest, much of it provoked by wealth in mines that once produced 50 to 80 percent of the national budget.

Katanga was the site of a secessionist war in the 1960s, and its politicians have been accused of trying to break away in more recent years.

The main conflicts were driven by tensions between the region's north and south, between natives and perceived outsiders, and between the army and Mai Mai militiamen who ran amok committing widespread abuses and now extort money from civilians.

The Mai Mai was supported by the Congolese government during the war with Rwanda and Uganda. After the war ended in 2003, the national government tried to integrate the Mai Mai into the national army, but without success. Mai Mai leaders became increasingly hostile to the government and took control of huge swathes of central Katanga, fought their former allies the Congolese army, and terrorized local communities.

A military court in Katanga convicted Mai Mai leader Gedeon Kyungu Mutanga in March 2009 of crimes against humanity. In its landmark ruling, the court also found the government liable for failing to disarm the Mai Mai militias and awarded damages to the victims.

The region where Gedeon operated became known as "the triangle of death" because of the suffering inflicted on civilians there. In November 2005, the United Nations estimated 150,000 people had been forced to flee their homes and hundreds had been killed.

U.N. troops are spread thin on the ground in a region the size of France.

Bas-Congo

Followers of Bundu dia Kongo (BDK) reject central authority over the western province of Bas-Congo and are campaigning for the re-establishment of the pre-colonial Kongo kingdom, which encompassed parts of present-day Angola, Democratic Republic of Congo and Gabon.

More than 100 people died in a January 2007 crackdown on the BDK, and dozens of BDK supporters died in clashes with police in early 2008. The police attempted to hide the extent of the carnage by dumping bodies in the Congo River and hastily burying others in mass graves, says Human Rights Watch. The government revoked the authorisation of the BDK to operate as a social and cultural organisation that same month, effectively making it illegal.

There's little U.N. presence on the ground, since more than 90 percent of its troops are in the east, but additional troops were sent in for a few months to help restore peace.

Many analysts categorise Congo's conflict as a "resource war" motivated by control over eastern Congo's rich natural deposits of gold, diamonds, copper, cobalt, timber and cassiterite, a tin ore.

Mining of coltan, a conductor used to make cellular telephones, increased instability in eastern Congo when it boomed in 2000. Rwanda and its army profited from the trade, according to researchers at British-based advocacy organisation Global Witness.

When the bottom fell out of the coltan market in 2001, producers switched to cassiterite, often found in the same places. The tin ore is used in lead-free circuit boards for electronic equipment and its rising value was heavily influenced by China's phenomenal economic growth.

The mining industry is unregulated and dangerous. Wages vary from $1 to $5 a day, says the U.S.-based Enough Project. Many gold miners only receive a bucket of sand - which may or may not contain some gold - at the end of a hard day's work. Thousands of children also labour in the mines.

During the coltan boom of 2000, so many people abandoned farming to work in the mines that there were shortages of the local food staple, manioc flour.

Profits from Congo's resources have historically been extracted by whoever controls the soldiers at the mine gates, making demilitarisation unattractive to those with bank accounts on the receiving end, including politicians in Kinshasa.

Western security sources are worried that Congo's lax security could be exploited by countries such as Iran to get their hands on uranium which might be used for nuclear programmes. Congo provided the uranium for the U.S. atomic weapons dropped on Japan in 1945, and its Shinkolobwe mines are in unstable Katanga province.

Former leader Mobutu diverted enormous sums into his own bank accounts, much of it from copper mines in Katanga. He built up a fortune while the state was deprived of funds to build infrastructure and services for the general population.

After nationalising foreign-owned mines in the mid-1960s, Mobutu encouraged local entrepreneurs - usually his friends and relatives - to take charge of guarding their own territory, setting the pattern for the present day.

Historians say Mobutu was following in the footsteps of Belgian colonialists, who forced huge swathes of the population to work on rubber plantations that funded lavish palaces for the Belgian monarchy.

Colonial administrators instituted a brutal system of slavery, demanding employees account for every bullet used with the hand of the slave who had been shot.