BEIJING, Nov. 10 (UPI) -- A gas leak Thursday in a coal mine in China killed at least 20 miners and 23 others remained trapped, local authorities said.

The leak, the latest in a number of coal mine disasters in China, occurred at the privately run Sizhuang Coal Mine in Qujing city in southwestern Yunnan Province, the official Xinhua news agency reported, quoting the provincial emergency response office. Hundreds of rescuers had been summoned to save the trapped miners.


The report said a preliminary investigation showed a gas leak occurred at one of the platforms inside the shaft and it spread to another platform. An earlier report said the disaster was the result of a gas explosion, Xinhua said.

The coal mine has an annual output capacity of 90,000 tons, the report said.

Last Saturday, 45 coal miners were rescued after being trapped for more than 30 hours following a "rock burst" in a coal mine in central China. Eight other miners died in the incident.

An explosion late last month in a coal mine in southeastern China's Hunan province killed 29 workers.

China has been plagued by coal mine disasters in recent years despite massive efforts to improve safety and crackdowns on illegal mines. Studies have said millions of coal miners in China are migrant workers, many of whom are not adequately trained in basic safety rules.