A methane gas explosion in a private coal mine in south-west Pakistan has killed eight workers, a mining official has said.

The incident happened on Monday when 200 miners were digging to reach a coal deposit at the mine, located in Duki village, Balochistan.

The workers had reached 600ft below ground when the blast occured.

Provincial chief mining inspector Iftikhar Ahmed stated that eight of the workers were killed immediately, while two others were found unconscious and were moved to a nearby hospital.

Ahmed told AFP that dozens of miners, angered over the incident, rallied at the mine on Monday to demand action against the owner.

Miners have accused the owner of ignoring safety measures, said Ahmed, and authorities have opened an investigation to determine what caused the blast.

Mining accidents are common in Pakistan. In March 2011, 43 workers were killed following an explosion at a different coal mine in Balochistan, leading to its collapse.