The death toll from a gas explosion at a coal mine in southwest China has risen to 26 and rescue workers were trying to pull out another 21 still trapped underground, state media said Thursday.

A total of 154 miners were working underground at the Xiaojiawan mine in the city of Panzhihua in Sichuan province when the blast occurred on Wednesday afternoon, the official Xinhua news agency said.

Rescuers had pulled 107 people out of the mine by Thursday evening and rushed 51 of them to hospital, it said.

Rescue efforts were still under way and the individual responsible for the mine has been detained, the city government said on its website.

But efforts to save the miners has been made difficult by high temperatures and the presence of poisonous carbon monoxide in the mine, Xinhua said.

China's mines are known for being among the world's most deadly due to lax regulation, corruption and inefficiency, and accidents are common as safety is often neglected by bosses seeking quick profits.

Latest official figures show 1,973 people died in coal mining accidents in China in 2011, a 19 percent fall in fatalities compared to a year earlier.

Labour rights groups, however, say the actual death toll is likely to be much higher, partly due to under-reporting of accidents as mine bosses seek to limit their economic losses and avoid punishment.

China is the world's leading consumer of coal, relying on the fossil fuel for 70 percent of its growing energy needs.