Chinese authorities say the number of coal miners trapped underground by flood waters in Shanxi province has risen to 57.
China's state-run media say a senior Chinese official blames Thursday's accident on "excessive and illegal" production by the coal mine's management.
China's Xinhua News Agency quotes the director of China's Work Safety Administration, Li Yizhong, as saying the miners were working in a coal seam beyond the mine's approved limits when the flood occurred. He also said the mine in Zuoyun county was producing far above its approved capacity.
The Chinese official also said the management of the mine was so poor that it was not clear how many miners were missing after the flood.
Nine managers of the Xinjing coal mine were detained after they initially claimed that only five miners were missing. The head of the mine remains at large.
Chinese state media also reported that managers tried to send relatives of the trapped miners to nearby Inner Mongolia to keep them from talking to the media or rioting.
About 100 miners managed to escape the flood.
China's mines are the most dangerous in the world, and officials have repeatedly pledged to crack down on negligent mine operators. Almost 6,000 Chinese miners were killed in accidents across the country last year.Some information for this report was provided by AP and Reuters.