China’s work safety watchdog has called for enhanced supervision of major coal mines after 17 miners died when an elevator used by workers fell down a shaft in Northeast China’s Heilongjiang province on March 9.

The State Council Work Safety Committee said on March 16 that it will launch a targeted campaign to check the safety of equipment at major coal mines across the country to reduce safety hazards.

It came after the elevator in the Dongrong Second Mine at Longmay Mining Holding Group’s Shuangyashan branch fell after its electric cable caught fire and burned out the steel wire lines, killing all 17 miners inside.

The mine was later found to be unsafe as the cage was not equipped to prevent such a plunge, the committee said.

Police have detained two welders, accusing them of violating safety regulations. The manager of the mine also has been suspended, Xinhua News Agency reported.

The committee called on local work safety watchdogs to organize targeted campaigns to check other coal mines, especially elevators, to ensure their safety.

The March 9 accident was the second that day. An accident in Changzhi, Shanxi province, killed three miners and left two others injured.

Since February, four coal mine accidents have killed a total of 30 people.

“The accidents have exposed problems” related to work safety at some coal mines, the work safety committee said.

The accidents have also highlighted problems such as the lack of equipment maintenance and substandard safety management, it added.