An operation to rescue hundreds of people taken hostage when a train was hijacked by a separatist militant group in remote south-west Pakistan has continued into its second day, with dozens killed in the onslaught.

On Wednesday, Pakistan’s security services claimed to have rescued about 190 people who were being held captive after militants from the Baloch Liberation Army (BLA) blew up a railway line and launched an attack on the Jaffar Express train.

The hijacking took place as the train, which was carrying about 450 passengers, was travelling through a tunnel in the rugged mountains of Balochistan province on Tuesday afternoon.

Officials said that by Wednesday about 30 militants had been killed, as military and security personnel launched an air and land offensive to take back control. However, the efforts were hindered by the remote, treacherous terrain, which has made communication and mobilisation difficult.