An explosion at a coal mine in central China has killed 20 miners and trapped another 17 underground.
Rescue efforts are underway at the pit in Yuzhou, Henan province, which state media said had been hit by a "sudden coal and gas outburst".
China's mining industry is the most dangerous in the world - more than 2,600 were killed in accidents in 2009.
The government has shut down more than 1,000 illegal pits this year as part of efforts to improve safety standards.
The blast happened in the early morning at the Yuzhou pit, which is owned by Pingyu Coal & Electric Co Ltd, the official Xinhua news agency reported.
The national work safety agency said 239 miners had managed to reach the surface but that 20 had been found dead and a further 17 were still missing.
Rescue operations are continuing to find the missing men, but an official surnamed Li told the Associated Press news agency it was not clear how far underground they were.
China is heavily reliant on its mining industry, with coal supplying some 70% of its energy needs. Many of those employed in mines are migrant workers with limited training.
The central government has made improving conditions in the country's 25,000 coal mines a priority, and the number of deaths has fallen from nearly 7,000 in 2002 to 2,631 last year.
In April, 115 miners were rescued alive from a flooded mine in Shanxi province after spending more than a week underground.
The National Energy Administration (Nea) closed 1,539 small and dangerous coalmines this year as part of restructuring efforts, said Xinhua.
But safety rules have often been ignored in favour of profit, as the economy has boomed.
Earlier this month, new regulations came into force requiring the managers of coal mines to accompany their miners, as an incentive to improving the conditions underground.
Any mine boss who refused to go into the pit would be given a harsh fine.
The latest accident comes after the successful rescue of 33 miners in Chile, after they were trapped for 69 days by a rock fall.
Many in China have said the country should learn from the incident and improve the training given to miners.