The death toll from a militant hijacking of a train in Pakistan's southwestern mountains has risen to 31 soldiers, staff and civilians, the military said on Friday as it accused India and Afghanistan of backing the insurgents.

The militants, Baloch ethnic fighters, said they would kill dozens of seized security personnel if the Pakistani government did not agree to a prisoner exchange.

Hostages freed after a day-long ordeal following an attack by militants on a train in Pakistan's Balochistan province described crouching on the floor for hours before their release, as the bodies of 25 people killed arrived in Quetta.

Mehboob Hussain was riding the train home on Tuesday when the tracks under the front car exploded. In the depths of central Pakistan's Bolan Pass, a pocket of wilderness so remote that there is no internet or mobile network coverage, the nine-coach Jaffar Express ground to a halt. Then the bullets started flying.

The BLA said they gave the Pakistan Army 48 hours to exchange prisoners of war, but since they did not heed their warning, they killed the hostages

Insurgents who attacked a passenger train carrying 440 passengers in restive southwestern Pakistan killed 21 hostages before

By bno Chennai bureau The Balochistan Liberation Army (BLA), a separatist militant group, attacked and held hostage the Jaffar Express, a passenger train traveling from Quetta to Peshawar in Pakistan between March 11 and 12.