US senior administration official said yesterday a Chinook helicopter that crashed, killing 31 US special operations forces and seven Afghan soldiers, was apparently shot down by insurgents.
It was the highest number of American casualties recorded in a single incident in the decade-long war in Afghanistan.
Twenty-five of the dead were US Navy SEALs, US television network ABC News reported.
Afghan President Hamid Karzai sent his condolences to US President Barack Obama, according to a statement issued by his office.
Taliban claims to have brought the helicopter down in a rocket attack but it has been known to make exaggerated claims.
NATO said there ‘‘was enemy activity in the area’’.
The helicopter was brought down during an anti-Taliban operation in an insurgent-infested district of the eastern province of Wardak, just south-west of Kabul.
It was shot down by a Taliban rocket that destroyed it, the Wardak governor’s spokesman said after the Taliban had claimed responsibility.
The death toll was given in a statement issued by Mr Karzai’s office and was not immediately confirmed by the NATO-led International Security Assistance Force.
During a joint special operation last night a helicopter crashed and as a result 38 people lost their lives. Among the dead, seven of them are from the Afghan Special Commando Army and the other 31 victims are international forces,” said Zaher Azimy, spokesman for the Afghan defence ministry.
A statement from the Afghan presidential palace said the helicopter crashed in central Maidan Wardak province to the west of the capital Kabul.
The Taliban issued a statement claiming to have shot down the Chinook during a firefight which also killed eight insurgents.
Azimy would not be drawn on the possible cause of the Chinook crash saying: "The incident is already under investigation. As this helicopter belongs to international forces, obviously they will provide details of the crash and the reason.