Rescue workers on Sunday freed 11 people who had been trapped hundreds of meters below ground in a gold mine in northern China's Shandong province.

They were among 22 miners caught in a blast in the Hushan mine in Qixia, a major gold-producing region, on January 10.

The first man was brought to the surface at around 11 a.m. and was in an "extremely weak" condition, according to a post on state media CCTV's Weibo microblogging site.

Video footage showed him being lifted out of the mine shaft with a black blindfold across his eyes. He was covered in a blanket before being carried away by rescue workers and taken to hospital for treatment.

Hours afterwards, another three miners were rescued from a different part of the mine. Three more were later pulled to safety from the same section. The rest were rescued shortly after.

They were from a group of 10 miners who had been in contact with rescue teams, while the first man had been trapped in a different section of the mine.

Major rescue effort

On Thursday, officials had warned it could take another two weeks to clear "severe blockages" before they could drill shafts to reach the 10 men.

But rescuers cleared an air ventilation shaft on Sunday and were able to free them earlier than expected.

Rescue teams have had no contact with a further 11 miners, state news agency Xinhua reported last week. One miner is known to have died from head injuries.

Authorities have detained the mine's managers because they waited more than a day to report the explosion.

Safety has improved in Chinese mines in recent years. However, accidents and deaths are still common as several mines cut corners on measures.