The mine safety administration said in a report on its website that the mine owners would be placed under detention, the company's offices sealed and bank accounts frozen while the cause of the accident was investigated.
In another incident in nearby Hebei province, at least 11 workers were missing after the entrance to a well in an illegal iron and gold mine collapsed, the stat-run Xinhua news agency said in a separate report.
|Shanxi province is China's biggest |
The accident occurred on Monday near the city of Chengde, Xinhua said, but did not explain the delay in reporting it.
China's coal mining industry is the most dangerous in the world with an average of 13 people killed by fires, explosions and floods every day.
In August, 181 miners died when heavy rains flooded two mines in eastern Shandong province.
Owners of Chinese coal mines have often been found to ignore safety rules and fail to invest in proper equipment in the quest for profits and the drive to meet the nation's booming energy demands.
The central government has previously spoken out against endemic corruption in the coal mining industry, with particular concern over collusion between local government officials and businessmen.
Official figures show that more than 4,700 coal miners died in China last year but independent labour groups put the toll at closer to 20,000 a year, saying many of the accidents are covered up.