Two workers were rescued as 33 miners were left trapped in a coal mine in western China following a gas explosion there.
An official at the Yongzhou district government propaganda office in the sprawling Chongqing region told the Associated Press reported that the condition of those underground was not known and rescue work was continuing on Monday morning. He refused to give his name, as is common with Chinese public servants.
The blast occurred shortly before noon, state media reported. Such accidents are often caused when a flame or electrical spark ignites gas leaking from the coal seam. Ventilation systems are supposed to prevent gas from becoming trapped.
China's mining industry has long been among the world's deadliest, although safety improvements and the closure of smaller, more dangerous mines have reduced the death toll in recent years.
China is the world's largest producer and consumer of coal but has announced plans to shutter more than 1,000 outdated mines. The head of China's State Administration of Work Safety said this year that struggling coal mines might be likely to overlook maintenance.