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.

Pakistan’s restive southwestern province of Balochistan has been the scene of a yearslong insurgency, with a surge in attacks in recent years

Pakistani security forces are carrying out a rescue operation to free dozens of passengers taken hostage by separatist militants who hijacked their train in the southwest of the country on Tuesday. Here is a look at what happened,