A communications shaft is being broadened with an aim of rescuing a group of Chinese gold miners who have been trapped underground for 10 days, AFP reported, citing state media.

22 workers are stuck hundreds of metres underground at the Hushan mine in east China’s Shandong province after an explosion on January 10 sealed the entrance and cut off communications.

According to AFP, rescuers have made contact with 11 miners at a location around 1,900 feet below the surface, while one may be trapped about another 100 metres down. The whereabouts of 10 other workers are still unknown.

On Sunday, a handwritten note was sent up on a metal wire that rescuers had dropped into the mine. In it, the workers pleaded for food and medicine, along with warning that water levels were reaching alarmingly high levels in the mine.

Also read: What we know about China’s mining incident so far

At least four of the workers were severely injured, the miners added, with one of them ‘in a deep coma’.

“There are no professional rescue personnel (down there) and he cannot be treated intravenously,” Song Xicheng, deputy head of the rescue team, said according to AFP. 

Rescuers have already finished drilling two ‘lifeline’ channels to send food, medicine, and phones to the group.

According to AFP, eight more shafts are at various stages of drilling.

Hashtag “Shandong trapped miners sent another note” was trending on China’s Twitter-like social networking site Weibo and had received more than 170 million views by Wednesday morning.

Mining accidents are common in China due to poor enforcement of regulations. In December last year, 23 workers died after being stuck underground in the city of Chongqing.