The latest blast took place in Wenshan county, in the south-western province of Yunnan, at about midday on Monday.

The accident happened in an unlicensed mine, where 35 men were working - 10 of them were injured and taken to hospital.

Mining accidents are very common in China - more than 5,000 workers were killed last year alone, according to official statistics.

Our correspondent in Beijing says the unofficial figure is thought to be at least double that.

Also on Monday, 18 workers suffocated to death in a coal mine in Hunan province when natural gas started leaking into a mine shaft, Xinhua news agency reported.

The accident happened near Loudi city on Monday night, said an official of the city mine bureau. The mine was properly licensed and had a good safety record, he said.

About 30 men were in the mine at the time, and 12 escaped, the official said.

Death traps

In the third accident, seven workers were killed on Sunday at small mine in Shangli county Jiangxi province that had previously been shut down but was operating illegally, the Xinhua Daily Telegraph reported.