Rescuers pulled seven injured miners to the surface and were trying to reach 50 others trapped after a rock explosion in a coal mine in central China, state media reported.
Four miners were killed in the blast yesterday evening and 14 managed to escape, the official Xinhua News Agency said.
The rock explosion happened just after a small earthquake shook near the mine in the city of Sanmenxia in Henan province.
State broadcaster CCTV showed rescuers in emergency gear carrying out the seven found alive this morning. Xinhua said six had minor injuries but one was seriously hurt.
At least 200 workers were digging a small rescue tunnel about 1,650 feet deep to try to reach the trapped miners, the People’s Daily newspaper’s website said.
The structural status of the mine and the conditions of the miners were not known.
The Qianqiu Coal Mine belongs to Yima Coal Group, a large state-owned coal company in Henan, the State Administration of Work Safety said on its website.
Xinhua said a magnitude-2.9 earthquake occurred to the east of Sanmenxia about 30 minutes before a “rock burst”.
The phenomenon occurs when settling earth bears down on mine walls and cause a sudden, catastrophic release of stored energy. The exploding chunks of coal and rock, or the shock waves alone, can be lethal.
The survival of the trapped miners depends on the intensity of the rock explosion and the rescuers’ ability to provide ventilation to them, a local official said.