A US-led coalition military transport helicopter crashed while conducting combat operations in the remote mountains of eastern Afghanistan, killing all 10 American soldiers on board, a US military spokeswoman said today.

The CH-47 Chinook crashed late Friday while on a mission in support of Operation Mountain Lion, an offensive to root out Taliban and Al-Qaeda militants near the border with Pakistan. The crash was not the result of enemy fire, said Lt Tamara D Lawrence, a coalition spokeswoman.

“The remains of all the 10 soldiers have been found and there are no survivors,” she said. “There is no indication that the helicopter came down due to some enemy action.”

The soldiers were part of a more than 20,000-strong coalition force, mostly operating in the volatile south and east of Afghanistan. About 18,000 of those forces are American.

The helicopter was conducting “operations on a mountaintop landing zone” when it crashed near Asadabad in Kunar province, about 240 km east of Kabul, the military said in a statement. Rescue and recovery operations began at daybreak today, Lawrence said. An investigation into the crash is under way.

Some 2,500 Afghan and US soldiers are conducting a joint military operation in Kunar, one of the biggest since the ouster of the hardline Taliban regime by US-led forces in late 2001 for hosting Al-Qaeda.

Asadabad is surrounded by rugged mountains, and a large US military base there houses hundreds of troops.

The police chief of Kunar province, Gen Abdul Ghafar, said the helicopter crashed about 20 km northwest of the US base in Asadabad. He said the crash was a day’s walk from any passable road. “The area of the crash is a mountainous area and it is difficult to reach,” Ghafar said.