At least nine people have been killed in a coal mine accident in central China's Henan province.

State media said on Tuesday that rescuers are trying to reach the seven others still trapped.

Lethal gas is said to have started leaking into the mine late on Monday night.

The "gas outburst" occurred at the Sanyuandong coal mine in Dengfeng, a city in Henan province, the official Xinhua News Agency reported.

Deadly mining industry

Xinhua also reported 127 miners were underground and 111 escaped unharmed,
quoting an official with the Zhengzhou Coal Industry, which runs the mine.

Over the weekend, 24 workers were trapped in a flooded mine in northeast Heilongjiang province, while a blast at a workers dormitory at another mine in the northern city of Linfen in Shanxi province killed at least 17 people.

China's mining industry is the world's deadliest with accidents killing more than 2,600 miners throughout the country last year.