Rescuers pulled seven injured people from the disaster site in Wulong county in Chongqing municipality, the official Xinhua news agency said.

"Millions of cubic metres of rock flooded a valley, burying an iron ore plant and six houses," it said.

China's mines are the deadliest in the world, due to lax safety standards and a rush to feed demand from a booming economy. More than 3,000 people died in coal mine accidents in 2008 alone.

Last September, a mudslide caused by the collapse of a mine waste reservoir in northern Shanxi province killed more than 250 people.