BEIJING (AP) — A coal mining accident in southern China has left 10 dead and five injured, local authorities said Wednesday.

The Pu'an county government in Guizhou province said on its website that 56 of those in the mine had safely reached the surface and rescue work was continuing. It wasn't clear whether any miners remained unaccounted for.

The notice did not give a cause for Tuesday night's accident, although the official Xinhua News Agency says it appeared to have been a gas explosion. Such blasts are usually caused when poor ventilation leads to a buildup of highly volatile coal gas inside the shaft.

China's mining industry has seen a dramatic improvement in safety, with deaths falling to under 1,000 last year from more than 6,000 per year a decade ago.

At the same time, demand for coal has plateaued as China's economy decelerates from the headlong rush of the last decade. China is also attempting to cut coal consumption to reduce some of the world's worst air pollution in Beijing and other cities.