山东4矿工井下被困36天后获救

The four miners have been named as Guan Qingji, Hua Mingxi, Li Qiusheng and Zhao Zhicheng.

They were brought to the surface one after another through an specially drilled access shaft between 9:20 and 10:50 local time, late on Friday.

They are now receiving treatment at a local hospital.

The medical staff said they suffered no major injuries and may be able to join their families before the Spring Festival, next week.

The gypsum mine collapsed on the Christmas Day in Pingyi County, when 29 miners were working underground.

Eleven of them were saved immediately after the accident with one confirmed dead.

The rescue team later drilled four small tunnels to help locate the four trapped in a space no longer than 50 meters.

Fu Wei with Shandong Provincial Work Safety Bureau said the largest difficulty for the rescue operation was dealing with the precarious geological conditions.

"The two biggest obstacles were continual cave-ins and water outbursts underground that had threatened the lives of rescuers and forced the rescue operation to be suspended several times."

To reach the miners, the rescuers drilled a shaft more than 220 meters deep through limestone, sandstone and gypsum.

Du Bingjian with the National mine rescue team said this was the first time that a rescue process such as this had been used in China, which brought uNPRecedented difficulties.

"We had never operated a rescue this way. Continual cave-ins had led to structural distortion in the mine that is still worsening. It's difficult to drill holes while taking preventive measures in such a circumstances."

Around 1,000 people have been working over the past month on the rescue operation.

13 other miners are still missing.

The owner of the mine committed suicide by jumping into a flooded shaft in the earlier days of the rescue.

The county's Communist Party chief, government head and two deputy heads have been sacked following the accident.

Several executives of the mine are under police investigation.

For CRI, this is Li Jianhua.