At least 20 workers are dead and 23 others are trapped underground following a blast in a China coal mine.
A local mine safety official said a “coal and gas outburst” from a coal face had trigged the accident.
The official China News Service said efforts to rescue those trapped were be hampered by the risk of explosion from the high levels of gas that had escaped during the blast.
According to US ABC News the privately run Sizhuang Coal Mine in Quijing city in southwest China was operating illegally and its license had been revoked a year ago.
Hundreds of rescuers are working at the scene, and ventilation machines are being used to pump methane gas out of the mine to allow fire-fighters to enter.
China’s coal mines are the deadliest in the world and late last month a separate gas explosion killed around 28 miners.
In 2010 2433 people died in coal mining accidents in China, a rate of around six workers per day.
However the country is working to improve safety standards and shut down smaller illegal mines.
In 2002 the country's mining fatality rate reached an annual high of nearly 7,000 deaths.