A rescuer said most of the trapped miners were from the provinces of Shanxi, Hebei, Hunan and Guizhou.

Dangerous industry

"Both the president and the premier have come out to talk about making this a major priority," Al Jazeera's Melissa Chan, reporting from the Chinese capital of Beijing, said.

"They also sent the vice-premier down to Shanxi to oversee rescue efforts personally.

"Of course there are a lot of coal mining accidents in China and this has been something the government has been working on very hard to limit the number of accidents in China, but it remains the deadliest country for miners to work in.

"Usually these cases occur in smaller mines, illegal even, but this is a major mine development so this does indicate that there are persistent problem across the board," she said.

At least 2,600 Chinese coal miners were killed in similar accidents last year.

The Wangjialing mine belongs to the state-owned Huajin Coking Coal company and was under construction when the flooding trapped the miners.

The mine covers about 180sq km while the mining zone holds an estimated 2.3 billion tonnes of coal reserves, including nearly 1.04 billion tonnes of proven reserves, the state-run Xinhua news agency reported.

It is expected to produce six million tonnes of coal each year once put into operation, according to Huajin Coking Coal's website.