Twenty-one miners were trapped underground after a coal mine in Pingtang County, southwest China's Guizhou Province, was flooded on Saturday morning, said an official with the county government.

The accident occurred at about 9:30 a.m. when 29 miners were working at two shafts of Niupeng Mine. Eight workers have already been back to the ground safely, the official said.

The rescue work is under way.