BEIJING: Chinese rescuers were racing to reach 21 miners trapped in a coal mine Friday, as authorities vowed to crack down on illegal digging operations which have spiked amid price surges for the fossil fuel.

The group were trapped when the mine flooded on Wednesday in Xiaoyi city, in northern China's coal-producing Shanxi province, prompting a huge recovery effort.

Hundreds of rescuers have been dispatched to the mine where three pumps are trying to drain out the water that has filled the underground pit.

State broadcaster CCTV said a narrow and concealed entrance to the illegal mine had hampered rescue efforts, as well as a lack of a proper map of the site.

Seven suspects have been detained over the accident, and police said they were searching for others -- including the mine's owner, reportedly a local villager who fled after the accident.

China generates about 60 percent of its energy from burning coal, and had ramped up output in recent months to ease an energy shortage that had caused power cuts and forced factories to close.

Authorities said Thursday that high demand for coal has pushed up prices and cases of illegal mining.

The Work Safety Committee of the State Council and the Ministry of Emergency Management called for coal-producing provinces to investigate illegal mines, saying those involved should face criminal proceedings.

Mining accidents occur frequently in China, where the industry has a bad safety record and regulations are often poorly enforced.

Nineteen miners died after being trapped underground in a single mine collapse in September.

And in January, 11 of a group of 22 miners were dramatically rescued from a collapsed mine in eastern China after they spent two weeks trapped hundreds of metres underground.

China's mine safety body said last week that improved workplace safety meant there had been 336 mine accidents in 2021 so far -- 59 fewer than last year.

However, it warned of an increased risk of incidents in December as mines sacrifice production safety for output as the end of the year nears. - AFP