Rescuers on Monday raced to save 22 miners trapped in a flooded coal mine in southwestern China, state media reported.

Flooding struck the mine in Yunnan province in the pre-dawn hours Monday, the official Xinhua news agency said.

A total of 26 workers were underground at the time, though four were rescued, the report said.

On Monday afternoon, "the 22 miners were still out of contact", Xinhua quoted Zhang Lei, deputy head of the rescue headquarters, as saying.

Zhang added, however, that the water level in the mine shaft was dropping as rescuers pump water out.

Three high-powered pumps and more than 500 people have been dispatched, said Zhang, who is also vice mayor of Qujing city where the mine is located.

Xinhua said an investigation was underway.

Accidents left 1,049 people dead or missing in 2013, the central government said on its website in January, down 24 percent from 2012, reflecting both risks and improvements in the country's thriving and often under-regulated sector.

The 2013 figure compared with 1,384 the year before and 1,973 in 2011.

China is the world's largest consumer of coal and its mining industry sometimes skirts safety regulations, although authorities have shut small operations in recent years to try to improve conditions.

Some rights groups, however, argue the actual figures for death and injury may be significantly higher due to alleged under-reporting by mining companies.

In December, 21 of 34 miners died in an explosion at Baiyanggou coal mine in China's western Xinjiang region, the official news agency Xinhua reported at the time.

In May last year, a total of around 40 miners died in two accidental blasts in Sichuan and Guizhou provinces in the southwest.

And an explosion at a coal mine in the northeastern province of Jilin killed 28 people in March last year.

Though often deadly, mine accidents are also survivable, one of the most dramatic examples being the 33 Chilean miners who were trapped deep underground in 2010 and were eventually rescued after 69 days in an ordeal that captivated the world's attention.