The explosion occurred at the powder magazine of the Xingdong No.2 Mine around 1:40 a.m, the administration said, adding that two rescue teams have been sent to the scene and started rescue operation.

The cause of the explosion still remains unknown.

A low gas-concentration mine, the coal mine has an annual production capacity of 90,000 tonnes.

Luo Lin, chief of the State Administration of Work Safety, has led a working team to the scene to guide the rescue work, the administration said.