The incident occurred when the train, travelling from Quetta to Peshawar and carrying 440 passengers, was ambushed by BLA militants near the mountainous terrain of Gudalar and Piru Kunri in a tunnel. The incident occurred when the train, travelling from Quetta to Peshawar and carrying 440 passengers, was ambushed by BLA militants near the mountainous terrain of Gudalar and Piru Kunri in a tunnel.