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.

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

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.

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.

Nearly 350 hostages were rescued at the end of a deadly standoff between Pakistan’s military and armed militants who hijacked a train in the southwestern Pakistani province of Balochistan, a security source told CNN Wednesday.

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.