Islamabad, July 4 Friday's helicopter crash in which 26 security personel were killed in the Federally Administered Tribal Areas' (FATA) Orakzai Agency, is being seen as a serious blow to the Pakistan Army ahead of the its planned all out offensive against the Tehreek-e-Taliban Pakistan (TTP) chief Baitullah Mehsud in South Waziristan.

The ISPR may have denied any foul play in the M-17 crash saying a technical snag had triggered the crash, but sources said that extremists hiding in the terrains targeted the military chopper with sophisticated artillery.

"This is a utility helicopter. Because of technical faults, it crashed in Orakzai.There is no operation in Orakzai. It was flying over from a destination in FATA and going back to Peshawar," the ISPR spokesperson Major General Athar Abbas said.

Reports of exchange of fire between the troops who were sent to the accident site to retrieve the bodies and carry out relief work, and the militants were also received, The Nation reports.

Military officials said that an investigation would be carried out into the crash, which according to them was caused by technical failure, as the M-17 pilot had put out a 'Mayday alert' just before the fatal crash.

Meanwhile, German news agency, DPA said that the Taliban has claimed the responsibility for shooting down the military chopper. (ANI)