A strong explosion rocked a coal mine in the southwestern Pakistan and local authorities are expressing fears that 12 missing workers are dead.

A search and rescue operation is underway at the Singidi mine in Balochistan province, where crews from Quetta have been rushed.

“Twelve workers were inside the mine when it collapsed” after the powerful explosion, which was attributed to a methane leak, said Abdul Yani, a provincial official.

Accidents are common in Pakistan’s mines, where working conditions are described as extremely dangerous and safety regulations are considered inadequate.

Last June, 11 people were killed in a methane leak at a United Coal Company coal mine in Balochistan province.