The death toll from a gas blast at a coal mine in Central China's Henan province has risen to 12, local authorities said Friday.
State news agency Xinhua reported a local safety watchdog as saying Thursday that seven workers remained trapped following Wednesday's collapse as they expanded a pipe way at a Dengfeng city colliery, causing a gas leak.
According to Dengfeng's publicity department, the bodies of the seven were discovered at 6 a.m. Friday (2200GMT Thursday).
Of the 51 Xingyu Coal Mining Co. Ltd. workers underground at the time of the accident, 39 managed to escape.
Xinhua reported an initial investigation as indicating that the accident was triggered by human error.
Chinese mines are among some of the most dangerous in the world due to lax regulations and poor operating procedures.
In recent years, the country has produced more than one-third of the world's annual coal output, but accounted for more than two-thirds of global mining deaths annually, according to the Mining Technology journal.
By Fuat Kabakci in Beijing
Anadolu Agency
enerji@aa.com.tr