Seven miners were trapped in a colliery gas explosion in northeast China's Heilongjiang Province on Monday, the local government said Tuesday.

The blast occurred at 4:30 PM at Hongyuan mine in Jidong County in Jixi City, a spokesman with the provincial coal mine safety watchdog said.

He said 29 miners were working in the pit when the accident occurred and 22 were rescued.

Rescuers are continuing to search for the seven missing.

Investigators said Hongyuan was a small mine designed to produce 60,000 tons a year. It was allowed to resume production only in April after a major safety overhaul.

(Xinhua News Agency May 16, 2007)