Helicopter crashes in Afghanistan

Seven people have died after a Nato Chinook helicopter crashed in Afghanistan, the alliance has said.

Five crew members and two military passengers were killed in the crash. US military officials said the dead crew members were Americans.

A Taleban spokesman said his group had shot down the aircraft, which came down in the southern province of Helmand.

Fighting between Nato and Taleban insurgents has escalated in recent weeks - particularly in the south.

'Enemy fighters'

The nationalities of the two military passengers are still unclear.

The helicopter crashed at around 2100 (1630 GMT) in the Kajaki district of Helmand, Nato's International Security Assistance Force (Isaf) said in a statement.

Rescue workers were ambushed by "enemy fighters" and were forced to call for an air strike to access the crash site, Isaf said.

Incidents of helicopters being shot down are relatively rare in the country, says the BBC's Alastair Leithead in Afghanistan.

About 30,000 alliance troops and another 10,000 US-led ones have been battling to boost the authority of President Hamid Karzai.

Nato is investigating the cause of the crash.

(CNN)