Fighting has intensified sharply in northwest Pakistan over the past two months since the Army went on the offensive to push back an expanding insurgency that raised fears for the stability of the nuclear-armed US ally.

The helicopter crashed on Friday because of a technical fault about 20 km from Peshawar on the mountainous border of the Orakzai and Khyber ethnic Pashtun tribal regions, the military said.

However, the Taliban claimed responsibility on Saturday for the helicopter crash, saying that they had shot it down.

“We shot down the helicopter,” a spokesman for Taliban insurgents based in the nearby Darra Adam Khel region told AFP by telephone.

The spokesman, identifying himself as Muhammad, said the helicopter had been targeted in retaliation for the Pakistani military operation in South Waziristan, a stronghold of the Taliban and al-Qaeda.

On Saturday, Army helicopters attacked a militant position in the same area, a Government official said.

“They struck a militant bunker on a peak. We went there after the attack and found 10 bodies lying there,” Khaista Rehman, said a Government official based in Kallay, the main town in Orakzai region.

All of the bodies from the crashed helicopter had been recovered, the military said.

The military has also launched air raids in the tribal belt to prepare for a second front against the Taliban in South Waziristan, a stronghold of feared warlord Baitullah Mehsud.

Fighter jets have been pounding suspected insurgent hideouts in South and North Waziristan, where the military says it is preparing for a fullscale offensive.

Military and Government officials have vowed to track down and eliminate the warlord blamed for a wave of deadly blasts in Pakistan in the past two years.