The accident happened yesterday at the Liangshuigou Coal Mine in Muzhuo township of Zhenxiong county, according to the county's publicity bureau.
An initial probe has indicated a gas blast in the mine.
Operation of the coal mine has not resumed after the Spring Festival, but the mine manager managed 20 miners to work in the mine without any safety check.
Twelve of them had been lifted out of the mine before the accident. The manager of the colliery has been in police custody.