Six people were still missing onWednesday and another 57 people were injured, the official Xinhua News Agency reported.

The first explosion occurred at about 6 am on Tuesday in Yizhou city in Guangxi province and the blasts continued until 1 pm. Fire spread over a nearly 10,000-square-metre area, Xinhua said, citing an unidentified firefighter in the rescue operation.

The government evacuated 11,500 residents in case of further blasts and chemical leaks.

Poisonous gases, mainly sulfurated hydrogen and carbon monoxide, were still coming from the site, Mr Ge Xianmin, Guangxi's toxic substances emergency center director, was quoted as saying.

Regional work safety authorities were investigating the cause of the blasts.

Mr Fan Yinfeng, an operator at the fire brigade under the Yizhou Public Security Bureau, said firefighters from nearby towns were mobilised to help.

'With explosions continuing and a fire raging, it is quite treacherous for rescuers, since there are huge hidden dangers amid the blasts, along with leaks of toxic gases such as ammonia and formaldehyde,' Mr Ma Dewen, the firefighter in charge of the rescue efforts, was quoted as saying by Xinhua.

The plant is in a development zone of Yizhou city and mainly produces chemicals for adhesives and paints, Xinhua said. It is owned by Guangxi Guangwei Chemical.

Thousands die each year in China from fires, explosions and other industrial accidents often blamed on insufficient safety equipment and workers ignoring safety rules. -- AP