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 Balochistan Liberation Army claims it killed 6 security forces and seized a Pakistani passenger train carrying about 500 people in a remote, mountainous region.

The train hijacking in south-western Pakistan represents a major escalation in the region’s long-running insurgency.

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.

After more than a day of fighting with separatist militants who hijacked a train carrying hundreds of passengers, Pakistan’s army said it had brought the insurgent attack to an end, but that 21 passengers and four paramilitary personnel had been killed.

The Baloch Liberation Army (BLA) claimed responsibility for the execution of 214 hostages after Pakistan refused to negotiate a prisoner exchange. The mass execution included only Pakistan security personnel,

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