The Baloch Liberation Army (BLA) confirmed it had attacked the Jaffar Express Train which was travelling from Quetta to Peshawar.

A statement from the separatist group said it had bombed the track before storming the train in remote Sibi district. It claimed the train was under its control.

Pakistani police told local reporters that they had received information that three people, including the train driver, had been injured in the attack.

Police added that security forces had been sent to the scene of the attack.

A Balochistan government spokesman told local newspaper Dawn that there were reports of “intense firing” at the train.

The BLA claims that it is holding a number of passengers including security officers hostage, and has warned of “severe consequences” if an attempt is made to rescue those it is holding.

However, officials have not yet confirmed that anyone is being held hostage.

Quetta’s railway controller Muhammad Kashif told the BBC that 400-450 passengers had been booked on the train but said they had no independent verification that anyone had been taken hostage.

A senior police official from the area bordering Sibi said “the train remains stuck just before a tunnel surrounded by mountains”, AFP news agency reports.

Meanwhile the country’s interior minister Mohsin Nawaz has condemned the attack and said he prayed for the speedy recovery of those injured.

Officials are yet to communicate with anyone on the train.

The area the express is stopped in has no internet and mobile network coverage, officials told the BBC.

Balochistan is Pakistan’s largest province and the richest in terms of natural resources, but it is the least developed. The Baloch Liberation Army has waged a decades-long insurgency to gain independence and has launched numerous deadly attacks, often targeting police stations, railway lines and highways.