The separatist Baloch Liberation Army claimed responsibility for attacking the train carrying 440 passengers in a tunnel in a remote part of Balochistan. Spokesman Jeeyand Baloch had said the group was ready to free passengers if authorities agree to release jailed militants.

Police say at least three people were injured in the attack and it is unclear how many people are being held hostage.

QUETTA, Pakistan (AP) — Pakistani security forces exchanged gunfire on Wednesday with hundreds of separatist militants as they sought to free about 300 hostages aboard a train in the country’s rugged southwest, officials said.