Six workers died and two more were in “critical condition” Sunday after a methane explosion at an ArcelorMittal mine in Kazakhstan, the company and the emergencies ministry said.

A sudden blast took place Sunday morning at the Abaiskaya coal mine operated by ArcelorMittal Temirtau, a Kazakh unit of the steel giant in the Central Asian country’s industrial Karaganda region.

Also Read | Iraqi Prime Minister escapes assassination attempt after explosive-laden drone targets his house

Sixty four workers were in the mine at the time of the accident, and 56 were able to get out, Six people died (and) two were injured,” the emergencies ministry said in a statement.

ArcelorMittal said the accident had taken place due to an “outburst” of gas and coal.

The company said the two injured workers were in “critical condition.”

A government commission headed by Emergencies Minister Yury Ilyin was dispatched to the scene.

Mining accidents are fairly common in former Soviet countries due to lax safety practices and outdated infrastructure.