Six workers were killed in a powerful gas explosion in a coal mine in Pakistan's southwestern Balochistan province, a media report said on Sunday.

All the victims were working in the coal mine in the Shahrag coal field area of Harnai district in the province when the explosion took place on Saturday, Dawn newspaper reported.

A portion of the mine had collapsed after the explosion, leaving all the miners trapped.

Rescue teams and other miners in the vicinity rushed to the site to help the trapped and retrieve the bodies, it said.

All the victims belonged to the Shangla area of Swat.

Talking about the incident, Chief Inspector of Mines Ghani Baloch said a fire erupted after the gas explosion some 1,500 feet deep inside the mine, which blocked its mouth.

He said rescue teams have so far managed to recover five bodies.

“One body is still buried under the debris,” the official said, adding that the incident took place at 9 am on Saturday when the miners were digging out coal.

A probe has been ordered into the incident.

Last week, a gas blast at a coal mine in Orakzai tribal district of Khyber Pakhtunkhwa province killed nine workers and injured four others.