Four people were killed and nine are missing after an explosion at a coal mine in southern China, state news agency Xinhua reported Tuesday.

The accident occurred at 9.10 pm on Monday (13.10 GMT) at the Zimujia coal mine in Guizhou province, in the south of the country, according to local authorities.

Rescue teams are working to rescue the nine missing.

Chinese mines, especially coal mines - the country's main source of energy, have a high accident rate and are among the most dangerous in the world, although in recent years the number of fatal accidents has fallen significantly.

In 2017, there were 219 accidents in Chinese coal mines with 375 deaths, a drop of 28.7 percent on the death toll of 2016 and 20 times lower than the figure recorded during the early 2000s, when up to 7,000 people fell victim to mine accidents each year.