Rescuers drilled three more channels on Tuesday as they race against time to extract the 22 workers.

Workers trapped in a Chinese gold mine for more than nine days have received more medical and food supplies, including bandages, blankets and rice porridge, but one of the group is in a critical condition with a severe head injury, state media said.

A total of 22 workers were left trapped in the Hushan mine, in Shandong province, after an explosion on January 10.

A week later, it emerged that at least 12 of them were still alive as a note retrieved from the mine said: “We hope the rescue won’t stop.”

A drilled channel on Sunday located 11 of the miners, who were working more than 600 metres (1,968 feet) underground and rescuers were subsequently able to speak to them via a wired telephone.

But the progress of the rescue has been slow, according to Chen Fei, a top city official.

Rescuers drilled three more channels on Tuesday in an effort to extract the trapped miners [Stringer/AFP]

“The surrounding rock near the ore body is mostly granite … that is very hard, resulting in the slow progress of the rescue,” Chen told reporters.

“There is a lot of water in the shaft that may pose a danger to the trapped workers.”

Chen said the current food supply was only enough for two days.

‘Please speed up the rescue’

Rescuers drilled three more channels on Tuesday, according to a rescue map published on the Yantai government’s official Weibo account, a Chinese version of Twitter.

More than 300 people are involved in the rescue effort and excavators and machinery are on site but the teams have warned it will be extremely difficult to bring out the miners from the tunnel’s entrance.

The official Xinhua news agency said the miners had requested on Monday evening sausage and pickles as well as porridge but medical experts decided they should not eat hard food having only just regained their strength.

Fortified by the food and medical supplies – the fourth consignment to reach the group – two workers who had previously been very weak were able to walk again on Tuesday, Xinhua reported, citing a member of the rescue team.

However, the state-run newspaper People’s Daily said one worker was in a coma and in a critical condition, after sustaining a head injury in the blast, while two were “mildly unwell” and eight in good health.

One more worker has been located in another section of the mine, while the whereabouts of the other 10 remain unknown.

News that some of the miners are still alive has boosted Chinese netizens’ hopes for a miraculous escape, with thousands leaving prayer messages on Weibo and calling on the authorities to “please speed up the rescue”.

China’s National Mine Safety Administration has ordered a comprehensive inspection of the country’s non-coal mines, which will continue until the end of March, the People’s Daily reported.

There are 32,000 non-coal mines in China, most of which are small, use outdated technology and equipment and have poor safety management, it said, citing an administration official.