A toxic gas leak on Tuesday night at a garment factory in the southwestern municipality Chongqing has left five workers dead and three others poisoned, local officials said Wednesday.

The accident happened at about 10:20 p.m. at Chongqing 3533 Garment Dyeing General Factory.

Initial investigations indicated the poisoning was caused by excessive accumulation of hydrogen sulphide at the sewage processing workshop of the plant, sources with Chongqing municipal government told Xinhua in a phone interview.

The three poisoned were hospitalized, two of them were in critical condition.

It was the latest and most severe toxic gas leak among a string of such cases within a few days in the country.

Also on Tuesday, a hydrogen chloride leak from a chemical plant in Wenzhou in the eastern Zhejiang Province caused headaches and stomachaches among many residents nearby the plant, with some rushing their babies away from the area.

In north China's Hebei Province, about 100 villagers from Xushui County were hospitalized on Monday after they were poisoned by chlorine which leaked out of a recycling center.

While most of the toxic gas leaks were caused by human negligence, nature was also to blame in one case.

On Sunday morning, chlorine leaked from a chemical factory in southwest China's Sichuan Province after it was damaged by a rainstorm-triggered mudslide, sickening 125 people.