Islamabad: At least 15 people, including four women and two children, were burnt to death when unidentified armed men set a bus on fire in Pakistan's insurgency-plagued southwestern province of Balochistan, provincial officials said on Tuessday.

Four men attacked the bus as the driver stopped at a roadside eatery on Monday night in Sibi area.

Two entered the bus, which was on its way to Quetta from Peshawar. They sprinkled the vehicle with petrol and set it ablaze.

The attackers fled on motorbikes before police arrived. Further details were not available.