A blast at a coal mine killed at least 34 workers in southern Pakistan, the provincial disaster agency said on Friday, adding rescuers were searching for more missing miners.

The explosion, caused by methane gas, tore through the mine near the capital of the resource-rich province of Balochistan on Thursday, sparking a rescue operation that ran into the night.

“According to information received from the deployed teams, 34x Dead bodies have been recovered,” southern Balochistan’s provincial disaster management authority said in a statement in the early hours of Friday.

“The joint rescue operation is still underway to locate and recover the remaining trapped miners,” it added, without specifying how many were in the mine when the explosion took place.

Mining accidents are common in Pakistan, particularly in Balochistan.

Pakistan’s poorest province and largest by landmass, Balochistan lags behind the rest of the country in almost every index, including education, employment and economic development.