QUETTA: At least 22 people were killed and dozens injured Tuesday when a powerful explosion ripped through a bus carrying Shia pilgrims in Balochistan's militancy-hit Mastung district.

The bus was coming from the Pakistan-Iran border at Taftan when it was attacked in Dringhar area, on the main Quetta-Taftan Highway in Mastung district, some 50 kilometres southwest of Quetta.

Shafqat Anwar, the Assistant Commissioner in Mastung, said the bus caught fire after the blast. Anwar added that at least 32 people were injured, which included 24 men and eight women.

Provincial Home Secretary Asadur Rehman Gilani said that two buses had been traveling together with security vehicles provided by the government and that the bomb struck one of the buses.

“Two vehicles of forces escorting the pilgrim’s buses were also damaged in the blast,” he said.

Gilani said investigators believed around 80 kilograms of explosives were used in the explosion, though it was not immediately clear what type of bomb was used or whether it was a suicide attack.

“Our priority is to shift the injured to hospitals,” he said, adding that women and children were also among the dead and injured.

Most of the injured were shifted to Combined Military Hospital for medical treatment, he added.

Emergency was imposed in hospitals to treat the injured.

Banned militant group Lashkar-i-Jhangvi has claimed responsibility for the bombing.

Chief Minister Balochistan, Dr Malik Baloch condemned the attack on the pilgrims' bus and ordered inquiry into the incident.

This incident comes only 20 days after an explosives-laden vehicle targeted a passenger bus carrying Shia pilgrims in Hazar Ganji area of Quetta, killing at one and injuring 34 others. The banned militant outfit Jaish al Islam had claimed responsibility for the attack on January 1.