A powerful bombing at a railway station in south western Pakistan killed 17 people and wounded 30 others, police and government officials said.

Mohammad Baloch, a senior police officer, said a bomb exploded when passengers were waiting for a train to travel to the garrison city of Rawalpindi from Quetta, the capital of the restive Balochistan province

A separatist group, the Balochistan Liberation Army (BLA) claimed the attack in a statement, saying a suicide bomber targeted troops present at the railway station. Police said they are investigating the claim.

Government spokesman Shahid Rind said the death toll from the attack was likely to rise as some of the wounded passengers were listed in critical condition.

Local media reported that at least 20 people died in the bombing.

TV footage showed the platform littered with passengers’ luggage.

The oil and mineral-rich province of Balochistan is Pakistan’s largest but also least populated province. It is also a hub for the country’s ethnic Baloch minority whose members say they face discrimination and exploitation by the central government.

Along with separatist groups, Islamic militants also operate in the province.

The BLA often targets security forces and foreigners, especially Chinese nationals who are in Pakistan as part of Beijing’s multi-billion dollar initiative to build major infrastructure projects.