Islamabad: At least four people were killed on Sunday when a blast rocked a rail track in Pakistan's Balochistan province when a train was passing by.

The explosion partially damaged the railway track and a coach of the Jaffar Express, which was going from Quetta to Rawalpindi, Geo TV reported.

Twelve people were injured and rushed to a Quetta hospital. Three of them were in critical condition.

The Jaffar Express, which has been targeted by improvised explosives devices in the past, was halted after the attack. No one claimed responsibility for the explosion.

(IANS)