Police have taken the director of the mine in for questioning, Xinhua reported.
Accidents in mines are common in China, where there are poor safety regulations and inefficiencies.
Earlier this week 21 people were killed in two coal mine accidents in the southwest and centre of the country.
About 2,600 miners were killed nationwide last year, official statistics said.
The government has tried to improve safety but efforts have been hampered by the widespread flouting of rules in the rush to extract natural resources to feed China's booming economy.