Ten workers trapped underground after an explosion on Jan 10 at a gold mine under construction in Qixia, Shandong province, have been confirmed to have died, a news conference in the city was told on Monday.

Ten bodies have been found and lifted out since Sunday, including the body of one worker who was confirmed dead on Wednesday, after rescuers cleared a way through debris blocking the shaft.

Police are conducting DNA tests on the bodies to verify their identities, Chen Fei, mayor of Yantai, which administers Qixia, said at the news conference.

Eleven workers were lifted to safety on Sunday. They are now undergoing treatment recommended by experts from areas including critical care, psychology, nutrition and cardiovascular health, said Qin Chengyong, leader of the medical rescue and treatment team.

"The 11 workers are in stable physical and psychological condition with no life-threatening risks," Qin said.

Rescuers are still searching for the last remaining worker. They have searched the space above the No 6 section, which is 698 meters from the mine entrance.

Search work below the No 6 section faces huge difficulties because there is a huge amount of water there, Chen said.

"We won't stop searching until we find the last worker," he said.

The location where nine of the deceased workers were found showed they died in a second explosion while trying to climb to a safe place after the first explosion, said Chen Yumin, team leader of the rescue team.

The first explosion, which occurred at around 1:15 pm on Jan 10, created a strong tremor and shattered the windows of a room at the entrance to the mine. Thick smoke flowed out of the mine following the explosion. The second explosion occurred at around 2:45 pm.

The explosions damaged the communications system, leaving rescuers in the dark initially on whether any of the trapped workers had survived.