US helicopter down in Afghanistan

A US military helicopter has crashed in Afghanistan, the military has said.

The Chinook helicopter went down in the eastern province of Konar while carrying troops, the statement said.

The cause of the crash was not known, nor was the fate of the passengers. A Chinook helicopter can carry up to 54 passengers plus a crew of four.

The military said the aircraft had been participating in an anti-guerrilla operation. It was the second US Chinook to crash in the country this year.

The BBC's Andrew North in Kabul says it appears that this incident is "more serious" than the previous crash.

Eighteen people were killed in that crash, which took place during a sandstorm in April.

It was the single heaviest loss of life for US troops since they invaded Afghanistan in 2001.

US military forces regularly come under attack in Konar province.

A man claiming to be a spokesman for Taleban told the BBC its supporters had shot the helicopter down, but there has been no independent confirmation of the claim.