Director General Lieutenant Gen Ahmed Sharif Chaudhry said 26 hostages were killed by the terrorists before the start of the army operation.

Baloch separatist militants blew up a railway track and launched rockets at the Jaffar Express, which was carrying over 400 passengers.

Pakistan's military accuses neighboring India of sponsoring militants in the restive southwestern Balochistan province, which saw an unprecedented attack this week by armed separatists.

Pakistan's military spokesman said on Friday the death toll in a train hijacking in the country's southwestern mountains had risen to 31 and he repeated accusations that neighbouring India and Afghanistan backed the militants who carried it out.

Separatist militant group the Baloch Liberation Army (BLA) claimed that they had taken hostages during an attack on a train carrying hundreds of people, including paramilitary troops, in southwestern Pakistan on Tuesday and threatened to kill them.

Pakistan’s prime minister has commended the country’s armed forces for successfully rescuing 339 passengers after a deadly train hijacking by insurgents in the southwest

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.