Six workers were killed and another one was injured in a cargon monoxide poisoning case in north China's Hebei Province, an official with the local government said on Saturday.

The accident occurred at 9:30 PM on Friday when two workers were immitting gas into the furnace at Shuanglong Metal Products Co. Ltd. in Nanggong City, he said.

The gas leaked from the valve of the gas pipeline, poisoning the two workers who neither wore respirators nor bought alarms with them as required by operation standards, he said.

Five workers who came to rescue were also poisoned by dense gas in the plant.

The workers were then rushed to a local hospital. Six died and one has been out of danger, a doctor said.

The private company has two blast furnaces, with an annual output of 600,000 tonnes of wires, the official said.

(Xinhua News Agency August 23, 2009)