Three people are dead and three are in hospital due to a leak of hydrogen sulfide gas on Tuesday in northwest China's Gansu Province, according to the Jingyuan county government.

The accident occurred at 12:30 AM in the Huaxia paper recycling factory, when one worker was cleaning a three-meter deep cellar used to pulp waste paper.

The worker collapsed unconscious and five colleagues also passed out as they tried to pull him out the cellar.

Three workers died despite emergency medical treatment.

A preliminary investigation shows all six were poisoned by condensed hydrogen sulfide gas triggered by the paper pulping process.

Further investigations are underway, and officials are looking into compensation for the victims and their families.

(Xinhua News Agency August 9, 2007)