Eight people were confirmed dead Friday in a mining accident in northwest China's Gansu Province after rescuers retrieved bodies of three more miners who died from carbon monoxide poisoning, local authorities said.

According to an official with the local government, rescuers had entered the lead-zinc mine and were searching for the remaining three trapped people late Thursday night after carbon monoxide levels had been reduced to safe levels.

On Wednesday afternoon three inspectors failed to return to the surface after entering the abandon underground pit 9 a.m. that morning to conduct routine inspections.

Eleven workers were then sent to look for them in the pit of the Changba Lead-Zinc Mine in Chengxian County, Longnan City. Of the 14 people who entered the mine, five escaped unharmed and one was later rescued.

Five people were confirmed to have died in the shaft from carbon monoxide poisoning Thursday afternoon.

The mine belongs to Baiyin Nonferrous Metal Group Co., Ltd., a major Chinese producer of non-ferrous metals.