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.

More than 400 people were on the Jaffar Express on Tuesday when militants fired on the train and blew up the track in the Balochistan region, Pakistani security officials said.

Twenty-one passengers were killed after a train in Pakistan was attacked and hundreds were taken hostage on Tuesday, according to the Pakistani military.