The accident occurred at about 5:05 pm at the illegal Yinguangshi Coal Mine in Lianyuan city of Hunan Province and by 22:00 16 workers had been confirmed dead and 21 others rescued.
Deputy director of the Hunan Coal Mine Safety Supervision Bureau, Yan Yinchu, said that the mine was operating without mining permits and the supervision department had asked the owner of the mine to stop production several times.
Rescue work continues and the investigation into the cause of the accident is underway.
Meanwhile, officials from Guizhou province confirmed that at least 10 miners were dead and nine others still missing in another coal mine accident which occurred on July 14 at Tongzi County's Maolong colliery when 19 miners were working.
According to China's official statistics for accident rates, over 4,300 miners died in a series of accidents during the first half of 2004.