134 miners are now reported killed in an explosion at a colliery in northeast China.
15 others are still trapped underground at the Dongfeng coal mine in Heilongjiang province.
It is the latest disaster to strike Heilongjiang, whose capital city, Harbin, was endangered earlier this month by a toxic spill into the Songhua river that provides its water supply, forcing a shut-down of tap water.
An explosion at a chemical plant in nearby Jilin province had poured 100 tonnes of benzene compounds into the river.
Investigators blamed yesterday's tragedy on a coal-dust explosion which knocked out all ventilation systems in the pit.
It is understood a gas explosion caused the coal-dust to ignite.
Chinese mines have one of the worst safety records in the world, with 3,000 workers killed in accidents so far this year.
Earlier this year the Chinese government set up a new department in an effort to improve the safety of mines.
And last week President Hu Jintao and Premier Wen Jiabao called for vigilance to prevent major accidents which cause huge casualties and property losses.
