Medics arrive at the entrance to a coal mine where a colliery gas burst at Tonghua Coal Mine in southwest China's Chongqing Municipality, on May 30, 2009. The accident has killed 30 and injured 59 miners.

Rescuers wait at the entrance to a coal mine where a colliery gas burst at Tonghua Coal Mine in southwest China's Chongqing Municipality, on May 30, 2009. The accident has killed 30 and injured 59 miners.

CHONGQING, May 30 (Xinhua) -- Death toll rose to 30 after five more bodies were recovered in a colliery gas burst Saturday in southwest China's Chongqing Municipality, according to local coal mine safety authorities.

The accident happened around 11 a.m. at Tonghua Coal Mine in Anwen Town of Qijiang County, when 131 miners were working underground. One hundred and one miners were rescued.

Of the rescued, 59 miners were injured, including four in serious condition.

The cause of the accident is being investigated.

The Tonghua Coal Mine, with a history of more than 50 years, is affiliated to the state-owned Songzao Mining Bureau of Chongqing. The colliery's designed production capacity is 300,000 tonnes per year, which now has been expanded to 600,000 tonnes.