Six miners have been found dead more than two days after a coal mine flooded in southwest China, local authorities said late Friday.

By 10:30 p.m., two miners were still missing after the accident occurred at the border of Dushan County in Guizhou and Nandan County in Guangxi Zhuang Autonomous Region, the Dushan county government said in a press release.

Rescuers were pumping out water and clearing sludge to reach the missing workers.

The rescue operation, however, was complicated by the high density of gas and narrow shafts.

Police have detained four owners of the illegally-operated mine.

In another accident, rescuers have found three bodies in a flooded coal mine in Guiyang, the capital city of Guizhou, with another 10 missing.

Rescuers were still working to relocate the workers who have been trapped for more than five days.