An explosion at a coal mine in China's south-western Guizhou province has left 21 miners dead, state media reports.
A further 10 miners were rescued or managed to escape following the blast at the privately-run Yuanyang colliery near the city of Anshun, said Xinhua.
Rescue work is continuing at the site as several unregistered miners were also thought to have been working underground.
Despite a safety drive, China's mines are among the world's most dangerous.
A rescuer working at the Anshun pit said five of the 10 known survivors had been taken to hospital suffering the effects of carbon monoxide inhalation.
"We arrived at the mine to carry out the rescue at midnight, and helped bring three of the survivors out of the shaft," the man, surnamed Zhao, told Xinhua.
According to official figures, 2,631 coal miners died in 1,616 mine accidents in China in 2009, down 18% from the previous year.
The government has stepped up efforts to improve safety in the mining industry in recent years, by enforcing regulations and taking measures to close unregulated mines.
In March this year, a massive search operation rescued 115 miners from a flooded pit in Shanxi province. Some had been trapped for about a week.
Officials accused the managers of the unfinished pit of ignoring warning signs and overcrowding the mine to speed up production.