SANMENXIA - Four people were confirmed dead and 57 others trapped underground after a rock burst occurred in a coal mine in central China's Henan Province Thursday evening, local work safety authorities said early Friday morning.

The accident happened around 7:45 p.m. in Qianqiu Coal Mine in the city of Sanmenxia, the Henan Administration of Work Safety said in a statement.

A total of 75 miners were working in the shaft at the time of the accident, of whom 14 managed to escape, the administration said.

Four people were confirmed dead and 57 others remain stranded as of early Friday morning, the rescue headquarters said, adding that the stranded miners still have chances of survival.

The shaft is about 760-meter deep and the rock burst blocked off the shaft at the depth of about 480 meters, which hampered the ongoing rescue efforts, according to the rescue headquarters.

A 2.9-magnitude earthquake hit the city of Sanmenxia at about 7:18 p.m. Thursday, and then a rock burst was reported from the shaft in the Qianqiu Coal Mine, according to the rescue headquarters.

The coal mine, with an annual production capacity of 2.1 million tonnes, belongs to Yima Coal Group, a major state-owned coal enterprise in Henan.

The State Administration of Work Safety has ordered local authorities to continue verifying the number of miners affected, working out rescue plans and preventing secondary accidents. Its head Luo Lin has arrived at the accident scene together with Henan Governor Guo Gengmao to direct the rescue.