From 1998-2000, Ethiopia and Eritrea fought a bitter war over their shared border, which killed at least 70,000 people and displaced 1.4 million.

Despite a peace agreement, a dispute continues to simmer over the unmarked border, centring on the small town of Badme. The United Nations has warned the stalemate threatens regional security and could trigger renewed conflict.

The two countries appear unwilling to resolve their differences, despite the efforts of an independent boundary commission, which first ruled on the border delimitation in 2002.

The 1,000-km (620-mile) border has never been properly demarcated. Before the war, people crossed it regularly to graze their herds, trade and find work. Most of Badme's estimated 5,000 residents voted in Ethiopian elections and used the Ethiopian Birr currency.

While the two governments were on friendly terms, this fluidity didn't pose a problem. But that changed as tensions grew. In July 1997 - four years after Eritrea gained independence from Ethiopia - Ethiopian troops temporarily occupied Eritrean territory in the east around Bada.

In response, the Eritrean government introduced its own currency and tried to regulate cross-border trade, leading to a dispute over where the border lay.

In May 1998, hostilities broke out around Badme, when Ethiopian soldiers opened fire on Eritrean troops. Eritrea occupied the Ethiopian-administered town, but it was recaptured by Ethiopia in 1999.

In 2000, after a temporary lull in hostilities, Ethiopian troops occupied a large part of southwest Eritrea.

During the two-year war, both sides bombed major towns, laid more than 400,000 landmines, and engaged in trench warfare, killing thousands of soldiers.

Tens of thousands of people fled or were expelled from both sides of the border - Ethiopians from Eritrea and vice versa. Hundred of thousands more in the conflict zones were internally displaced. At the time, the region was experiencing a food crisis, partly caused by severe drought.

After several attempts by the United States, the U.N. Security Council and the Organisation of African Unity to end the war, both sides agreed a ceasefire in June 2000, followed by the signing of a peace plan in Algiers in December.

Under that pact, a 25 km-wide (15 mile-wide) buffer zone was created between the two countries, to be patrolled by the U.N. Mission in Ethiopia and Eritrea (UNMEE) with a deployment of up to 4,200 troops.

An independent boundary commission was also set up under the Algiers agreement to decide on the exact location of the border based on past colonial treaties. Ethiopia and Eritrea agreed to accept the commission's decision.

In April 2002, the commission ruled on the boundary, but it was not until 2003 that it definitively awarded Badme to Eritrea, after an appeal from Ethiopia.

Both sides remain locked in a stalemate.

Eritrea has refused any diplomatic efforts that do not proceed directly to the enforcement of the border ruling. Asmara has blamed the international community - and the United Nations in particular - for failing to force Ethiopia to accept their shared border.

Ethiopia, for its part, has said it would only accept the commission's ruling after negotiations with Eritrea on the mechanics of how the border demarcation would take place.

In November 2007, the Hague-based international commission demarcated the line by current map coordinates in a ruling that Eritrea accepted but Ethiopia rejected. Having fulfilled its mandate, the commission then dissolved itself, leaving the two states to work it out themselves.

The impasse has raised fears of further conflict and left the U.N. peace force on the Ethiopian-Eritrean border struggling to do its job.

The force - now just 1,700 strong - has been at the border since war ended in 2000. But unable to enforce the commission's decisions, its relations with Asmara have become steadily colder.

Eritrea imposed fuel restrictions on UNMEE in 2006, culminating in a total shut-off in December - a move U.N. Security Council diplomats likened to blackmail.

In January 2008, Eritrean President Isaias Afwerki told the Security Council the force's continued presence on the border would be tantamount to occupation. Within weeks, UNMEE was forced to withdraw from the border by an Eritrean blockade of food and fuel.

Security Council members have said it is unprecedented for a country to stop cooperating with a U.N. force it has formally agreed to host.

While both countries insist they will not restart the war, both have moved tens of thousands of troops to the border.

Analysts say the tensions between the two countries are being played out in a proxy war in neighbouring Somalia and insurgent attacks in Ethiopia.

Thousands have been unable to return home since the war. Many have little option but to live in camps and temporary accommodation until the border dispute is resolved and mines are removed.

Eritrea in particular is suffering the after-effects, as most of the fighting took place on its territory. Its fertile farming region was heavily mined, and essential infrastructure destroyed.

The tensions have led to border closures, hampering trade. Both people and funds have been diverted away from farming to prepare for possible war.

Eritrean forces laid 240,000 mines and Ethiopian forces laid 150,000-200,000 mines during the border war, according to Landmine Monitor. Ethiopia is one of the 10 most mined countries in the world, with its northern Tigray region among the worst-affected areas.

In Eritrea, landmines were laid in some of the most populated and fertile parts of the country, including the Debub and Gash Barka regions. Debub is the country's traditional breadbasket.

Landmines put pastoral and other farm land out of bounds, and are one of the main reasons why people cannot return home or, when they do, have difficulty rebuilding their lives.

A combination of the border war and severe drought has left an estimated 2.3 million people from a population of 3.6 million in need of food aid, according to the U.N. Office for the Coordination of Humanitarian Affairs (OCHA).

More than 1 million farmers were displaced by the war, and the country's infrastructure was badly damaged.

The conflict was followed by one of the region's worst-ever droughts, which affected more than 60 percent of the population.

Nearly 19,000 men died in the war, and 300,000 are currently doing national military service. Up to 40 percent of households are now headed by females and are especially vulnerable to food insecurity, according to the World Food Programme (WFP).

The government has placed increasing restrictions on aid workers. In 2005, U.N. vehicles were seized and the government introduced taxes on aid imports and imposed size restrictions on non-governmental organisations. The U.S. Agency for International Development (USAID) was expelled, and the government reduced the number of people receiving free food aid from 1.3 million to 72,000.

Two more international organisations - the International Rescue Committee and Samaritan's Purse - were thrown out in 2006. The government said the peace deal in eastern Sudan meant cross-border operations were no longer necessary. The number of international agencies operating in Eritrea had fallen from 37 in early 2005 to 10 by the beginning of 2007.

Cereal production remains below the country's requirements, leaving it relying on commercial imports. The government's decision to integrate food relief provided by the World Food Programme into its cash-for-work programme has strained relations with donors even further.

Access to basic social services remains inadequate, especially in rural areas, where close to 70 percent of the population lack access to basic health services, and around 40 percent do not have clean drinking water.

Displacement

Since the end of the war, nearly 1 million displaced people have returned home but, according to the WFP, nearly half remain dependent on food aid. The ongoing border tensions and presence of landmines prevent them from accessing their own and communal lands. In May 2007, the government said more than 3,400 families had returned to their native villages or had been resettled in other areas.

There are still an estimated 45,000 internally displaced people (IDPs), most of them living in camps. According to the International Committee of the Red Cross, 85 percent are women and children.

Most of the IDP camps are in or near the U.N.-patrolled buffer zone. They have severe water shortages, little or no sanitation, and only half the children living in camps attend school, according to the U.N. children's fund.

Villages destroyed by the war in the buffer zone still need to be rebuilt. They lack water, transport and basic health and education services.

The Internal Displacement Monitoring Centre (IDMC) says the border war displaced 360,000 people in Ethiopia, mainly in the Tigray region near the Eritrean border. The United Nations estimates there are 62,000 people displaced in that region, most living in host communities.

As in Eritrea, landmines and continued insecurity have prevented many returnees from using their land, leaving them dependent on food aid.

According to the IDMC, many are unlikely to become self-sufficient until the frontier is demarcated, their lands de-mined and security improved.

According to a 2005 U.N. report, a lack of clean drinking water, sanitation, drugs and medical services in resettled parts of Tigray region has increased disease levels, especially diarrhoea.

There is little information on nutrition in the region, but Medecins Sans Frontieres Holland found acute malnutrition among young children at one site.