Mining accident in China kills 21

Twenty-one coal miners were killed after a roof collapsed at a coal mine in northern China, local media reported.

A total of 87 people were working underground in the Shaanxi province mine at the time of the accident on Saturday afternoon, official news agency Xinhua reported, citing local authorities.

Sixty-six other miners were rescued, the city government said in a statement.

The cause of the accident at the site, run by Baiji Mining, is still under investigation.

Deadly mining accidents are common in China, where the industry has a poor safety record despite efforts to improve coal production conditions and crack down on illegal mines.

In December last year, seven miners were killed and three others injured in an accident at a coal mine in China's southwest.

In October, 21 miners died in eastern Shandong province after pressure inside a mine caused rocks to fracture and break, blocking the tunnel and trapping workers. Only one miner was rescued alive.

According to China's National Coal Mine Safety Administration, the country saw 375 coal mining related deaths in 2017, down 28.7 percent year-on-year.

But despite improvements, "the situation of coal mine safety production is still grim," the bureau said in a statement following a coal mine safety conference last January.