Thirteen Pakistani army personnel, including three officers, were killed on Thurday when an MI-17 army aviation helicopter crashed in the mountains near Karak district in North West Frontier Province.

All the 13 military personnel travelling in the helicopter died in the crash in Chogi mountain in the remote northwestern tribal region, Pakistan Defence Spokesman Shoukat Sultan said.

Ruling out any militant attack, Sultan told PTV that the pilot of the helicopter reported technical problems to the ground control and headed for emergency landing but the chopper crashed in the mountains of Karak and later caught fire.

Pakistan currently deployed some of its troops in the in the tribal areas of South Waziristan adjacent to the NWFP to flush out Al-Qaeda troops holed in the border areas of Afghanistan.