Trapped Chinese miners found dead after blast

The dozens of coal miners who were trapped underground in a gas explosion earlier this week have all been found dead, reported Chinese state media on Wednesday.

The bodies of the last 15 missing miners were retrieved from the privately-owned Jinshangou mine near the southwestern city of Chongqing, the official Xinhua news agency said - bringing the death toll up to 33.

Only two workers managed to escape Monday's blast. Over 200 rescuers worked around the clock but were unable to find any survivors.

China's State Administration of Work Safety launched an investigation into the blast, "adding that those responsible must be strictly punished." Local officials also ordered smaller mines around Chongqing to temporarily shut down, according to information from Xinhua.

Although the cause of the explosion is still unknown, Xinhua reported that initial investigations showed that the coal mine was poorly ventilated, had malfunctioning equipment and exceeded its mining boundaries.

Gas explosions inside mines often occur when a flame or electrical spark ignites gas leaking from a coal seam. Ventilation systems are important for making sure gas does not become trapped underground.

Deadly mining accidents are common in China, the world's largest coal producer. At least 18 people died in a mine explosion in the Ningxia Hui Autonomous Region in September, while over 19 died in another coal mine accident in the northern province of Shanxi in March.

Struggling coal mines are likely to overlook maintenance issues, the head of the State Administration of Work Safety said earlier this year.

The county plans to close over 1,000 outdated mines as part of a plan to cut down on overproduction.

rs/sms (AP, AFP, dpa)