State media reported that Tuesday night's accident occurred at a mine in the city of Qitaihe in northeastern Heilongjiang province, a coal-mining region bordering Siberia. The cause of the accident was not immediately reported.

The director of the local coal production safety bureau, who gave his name as Liu, told The Associated Press that officials were trying to confirm exactly how many miners were trapped.

China is the world's top producer and consumer of coal. It announced plans earlier this year to shutter more than 1,000 underperforming mines, though hundreds of new coal plants are also under construction.

An October 31 explosion at a mine in the southwestern region of Chongqing killed 33 people, just weeks after a gas explosion in another mine in adjacent Guizhou province killed seven people.

China's work safety administration reported 931 coal mine accident deaths in 2014, down from the thousands of deaths reported annually in previous years, though government figures are often questioned for their accuracy. Official numbers for 2015 or 2016 were not immediately available.

Government officials are trying to balance the vast energy demands of the country with the world's largest population and the commitment China made to reduce carbon emissions as part of its ratification earlier this year of the Paris climate change agreement. With coal prices rising as winter approaches, China announced in October that "efficient coal producers" would be allowed to bypass an annual cap of 260 production days.