A total of 31 members of the US special forces have died in a helicopter crash in eastern Afghanistan.

The number of dead was confirmed by the office of the Afghan President, Hamid Karzai.

The helicopter came down yesterday in a Taliban district of the eastern province of Wardak, southwest of Afghanistan's capital, Kabul.

A spokesman for the NATO-led International Security Assistance Force (ISAF) said it was still looking into what had happened.

But an eyewitness told AFP that the helicopter had crashed as it was trying to take-off after landing on the roof of a Taliban commander's home during a firefight.

The incident is one of the worst of its kind in the 10-year war in Afghanistan.

Taliban spokesman Zabiullah Mujahid said the group was responsible for shooting down the helicopter, which he said was an American Chinook, and acknowledged that eight insurgents had been killed.

Chinook helicopters are often used for transporting troops and supplies and can carry up to 36 people, including crew, according to the US army.

