A U.S. military helicopter conducting combat operations has crashed in the mountainous area of eastern Afghanistan, killing all 10 American soldiers aboard.
A military spokesman ,Lieutenant Tamara Lawrence said there was no indication the crash resulted from enemy fire, rejecting a claim by Taliban insurgents that they had shot it down.
She said the remains of all 10 U.S. servicemembers were found at the crash site near Asadabad, the capital of Kunar province.
The aircraft was taking part in a large joint U.S.-Afghan military offensive called Operation Mountain Lion, and comes at a time of increasing attacks in Afghanistan's southern and eastern province.
Afghan President Hamid Karzai said he was deeply saddened by the deaths in Friday's crash.
News of the accident came as a U.S. counterterrorism official, Henry Crumpton, called on neighboring Pakistan to do more to eliminate safe havens in the lawless tribal lands on its Afghan border.
Officials said the Chinook was conducting operations on a mountain top landing zone when the crash occurred. A statement said additional aircraft and crews were also at the landing zone and confirmed that enemy forces did not cause the helicopter to go down.
An investigation is underway into the cause of the crash.
About 25-hundred U.S. and Afghan soldiers launched the offensive last month, aimed at rooting out Taleban and al-Qaida militants.