(CNN)Twelve miners trapped underground for more than a week in a Chinese gold mine have managed to get a note to rescuers, state media reported Monday.
The Xinhua news agency reports that the note confirmed 12 of the miners were still alive following the blast on January 10 in the city of Qixia in Shandong Province. Four are said to be injured while the fate of 10 others is unknown.
The workers wrote that they remained hopeful, according to Xinhua, but that they were in need of medical supplies.
Xinhua quoted the note as saying: "We are heavily exhausted and in urgent need of stomach medicine, painkillers, medical tape, external anti-inflammatory drugs, and three people have high blood pressure."
Rescue efforts have been underway since the blast occurred about 800 feet from the mine's entrance, trapping 22 workers around 2,000 feet below ground, the agency reported.
Rescue workers are reported to have first heard knocking sounds from those trapped on Sunday, followed by pulling on iron ropes.
Explosions and deaths are not uncommon in Chinese mines. In September, at least 16 workers in southwestern China died after they became trapped underground in a coal mine and exposed to unsafe levels of carbon monoxide, state media reported.
And in 2016, dozens of workers were confirmed dead after a gas explosion at a coal mine in the city of Chongqing.