Three workers died after accidentally inhaling poisonous gas at a private paper mill in Yibin, a city in the southern part of southwest China's Sichuan Province.

The tragedy unfolded at Yibin Hongyuan Paper Company when Deng Fubang, a worker in the company's workshop, lowered himself into a tank to carry out a maintenance check.

After entering the 3-metre-deep container, he suddenly fainted. Two co-workers rushed to the scene to try to rescue him, but they were overcome by the fumes and fell into the tank.

Xu Xingguo, a security guard at the site, said he tried to pull the trio to safety, but collapsed and fell into the container as well.

Emergency services were called and pumped oxygen around the area to try to clear the air.

The four men were pulled out of the tank and were taken to Shunan Hospital.

The three workers were later declared dead, while Xu, the security guard, is recovering.

The accident happened at about 4 AM on Sunday.

Li Tao, chief of the Internal Medicine Department at Shunan Hospital, said the gas that overcame the men contained firedamp, carbon dioxide and sulphur dioxide.

An investigation team is now investigating the cause of the accident.

Sources said the tank probably contained toxic substances.

Another team has been set up to support the family members of the victims and to try to arrange compensation.

Both of the teams are made up of members of the city's public security, production safety supervision and environmental protection bureaux, according to Yue Qidong, an information officer in the city.

The three victims had all worked for the company for about six years.

It produces brown paper and packaging material.

(China Daily June 13, 2006)