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NEW DELHI, Dec 5 (Reuters) - Operations appeared normal at New Delhi's international airport early on Friday, a Reuters witness said, despite media reports of a shootout there.

The Indian NDTV channel reported that two sharp sounds had sparked a security scare at the airport. But nothing was found after police swept through the terminal, and normal operations had resumed, it said.

The BBC website said earlier that reports quoting airport officials said Indian security forces had shot up to six gunmen there.

Indian is on heightened security alert after militant attacks in Mumbai that killed 171 people last week.

On Thursday officials said security alerts had been declared at three major airports, including Delhi and the IT hub Bangalore in the south. They said extra checks had been imposed on vehicles and luggage after warnings from intelligence agencies. (Reporting by Simon Denyer and Alistair Scrutton, editing by Mark Trevelyan)

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