The blast occurred at 1930 GMT on Tuesday at the Wangou
coalmine in Tonghua city, Jilin province, when 24 miners were working in the No 2 shaft, local officials and state media said on Wednesday.
"Three bodies have been recovered and 12 miners are missing," said a State Administration for Work Safety official. Nine miners escaped.
The mine, which had gone bankrupt, was ordered to stop production on 4 June, the Xinhua news agency said.
Coal mine accidents are frequent in China, a major coal producer and consumer, claiming 4150 lives during the first eight months of this year, the equivalent of 17 deaths a day.