The accident is the deadliest reported so far this year in China's coal industry, known for its poor safety record, Reuters reported.
It occurred at Baiji Mining Co Ltd's Lijiagou mine in the city of Shenmu at around 4:30 p.m. (0830 GMT) on Saturday, when 87 people were underground, the People's Daily said.
Sixty-six miners were rescued but 21 were trapped underground, it reported. Nineteen of the miners were confirmed dead at first while a search continued for the two missing miners; however, they were later found dead.
Some mining firms in major coal hubs in Shandong and Henan provinces and parts of northeastern China have received notices from the National Coal Mine Safety Administration asking them to halt operations for inspections that will last until June, the state-backed Shanghai Securities News (SSN) reported on Friday.
On Sunday, the Xinhua News Agency said that Shanxi province, which borders Shaanxi, would also carry out inspections at high-risk coal mines.