Three workers died and six suffered slight carbon monoxide poisoning in a leak at a chemical plant in north China's Inner Mongolia Autonomous Region Sunday.

Carbon monoxide began to leak at 1:05 p.m. when workers were checking the furnace gas purification system in a chlorine-alkali plant in Alashan League, the region's work safety supervision administration said Monday.

The plant belongs to the China National Salt Industry Corporation, the country's largest salt producer and seller.

The six poisoned were taken to hospital.

Administration officials said no further information was yet available, and they were investigating the accident.

(Xinhua News Agency March 2, 2009)