A deadly crash of a military transport helicopter in Pakistan may have been caused by overcrowding, an expert says.

An unidentified former aviation expert said the MI-17 helicopter involved in Friday's crash that killed 41 security personnel was designed to hold up to 32 individuals or 8,800 pounds of weight, Pakistan's Dawn newspaper reported Saturday.

Meanwhile, a security official, whose identity was not reported, said the victims of the Chapri Ferozkhel crash were given last rites Saturday morning.

Another unidentified official suggested the helicopter may have had too many troops on board because the military has been dealing with increased militant attacks.

The official said a recent upswing in regional violence promoted the road from Hangu to Parachinar to be closed, creating an increased demand for helicopter services.

The Dawn said the helicopter crash was being investigated by the aviation wing of the army.