"The gas blast at the Liuguantun Coalmine is an exceedingly grave accident caused by illegal operation," Li Yizhong, director of the State Administration of Work Safety (SAWS), declared Monday.

Li was referring to the blast at on Dec. 7 at the Liuguantun Coalmine in Kaiping District of Tangshan, a city in north China's Hebei Province. The blast killed 91 and left 17 others missing.

"There exist serious problems in the operation of Liuguantun Coalmine," Li said in a video conference on work safety.

Illegal production was the first problem, Li said, noting that the coalmine was still under construction and did not have a production licence.

The owner of the coalmine said his mine had not begun to produce or sell coal when the provincial government urged it to stop operating in July. But an investigation revealed that sales from the coalmine totaled 41,000 tons from March until the day of th e blast.

The original design of the coalmine had been changed without approval. The altered designed, which neglected safety considerations, allowed the exploitation from eight directions for a single coal layer without proper ventilative or gas surveillance systems.

Disordered management was also the major cause of the disaster, Li acknowledged.

According to a primary probe, the roll book showed that 186 workers checked in to work on Dec. 7, but 10 workers were found to not be present at their posts.

Many miners received almost no training before their work. Among the dead miners, eight of them were admitted by the coalmine on Dec. 6 and one of them on Dec. 7.

SAWS will take "resolute measures" to deal with the grim situation of coalmine safety, including enhancing supervision, standardizing coalmine resources and strengthening accountability, Li said.

(Xinhua News Agency December 13, 2005)