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 freed 190 hijacked train passengers held hostage Wednesday as the battle to free remaining hostages held by the militant group Baloch Liberation Army continued.

Separatist militants fired at a passenger train in southwestern Pakistan on Tuesday, injuring a train driver, police and railway officials said.