Police are hunting for the shareholders of a mine where a gas blast on Wednesday trapped 18 workers, officials said Friday.

Three managers of the Guaziyan Mine in Lianyuan City, central Hunan Province, are in police custody. But mine boss Wu Xiulin and more than ten other shareholders have fled after the mine's blast at 3:15 p.m. Wednesday.

High gas density and about 800 tonnes of debris in the tunnel have hindered efforts to rescue the 18 trapped miners, said Fu Jianhua, deputy director of the State Administration of Coal Mine Safety.

Fu said the 18 trapped workers had slim chances of survival. Thirty-two miners were working when the blast occurred, and 14 managed to escape.

As of Friday afternoon, rescuers had only transported about 30 tonnes of coal debris out.

The mine was operating illegally under an expired certificate, according to investigators.

Wu Hanqing, a township official in charge of mine safety, has been fired.

The township-owned colliery opened in 1997. It has an annual capacity of 30,000 tonnes but has sought to double that figure.

All coal mines in Lianyuan halted production for safety checks. The cause of the incident is under investigation.

(Xinhua News Agency December 19, 2008)