Pakistan- The Pakistan Army said Wednesday that it had retrieved the wreckage of an unmanned US spy plane that crashed in a tribal area along the Afghan border.

The crash occurred Tuesday night apparently because of a malfunction after the drone flew over the Afghan-Pakistan border, military spokesman Major Murad Khan said.

But local media reports cited witnesses saying the plane was shot down by tribesmen and security forces while flying at a low altitude.

It came down at Jalal village near Angoor Adda in South Waziristan, Khan said, adding that an inquiry had been ordered.

US forces deployed in Afghanistan have stepped up the use of drones to target suspected militant hideouts in Pakistan's tribal areas, which are sanctuaries of Taliban and al-Qaeda fighters launching crossborder attacks on international forces in Afghanistan.

But the US strikes have resulted in numerous civilian deaths, fuelling anger in Pakistan and putting a strain on relations between the two key allies in the fight against terrorism.

The Pakistani military has vowed to defend its territory. Earlier this month, Pakistani security officials said government forces and heavily armed tribesmen turned back US troops and helicopter gunships trying to cross its border by firing at them. (dpa)