BEIJING - A SERIES of explosions at a chemical plant in southern China killed at least four people, injured 44 and left another 17 missing on Tuesday, as hundreds of firefighters struggled to contain a spreading blaze, state media reported.

More than 10,000 residents within three kilometres of the plant were forced to evacuate the area in Yizhou city of Guangxi Zhuang Autonomous Region, the official Xinhua news agency said.

Ongoing explosions at the plant hampered efforts by firefighters to extinguish the blaze, which had spread over more than 10,000 square metres (110,000 sq ft), Xinhua added, quoting firefighters at the scene.

'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,' Xinhua said.

The report did not say whether local waterways might be affected by leaks.

Hundreds of firefighters were at the scene, and more were being asked to come from nearby cities, Xinhua said.

The plant, owned by the Guangxi Guangwei Chemical Co., mainly produces polyvinyl acetate, calcium carbide and vinyl acetate monomer - chemicals used in making paints, adhesives and coatings, Xinhua said.

The cause of the blasts was still being investigated, and it was not immediately known how many people were in the plant when the initial explosion occurred, Xinhua added. -- REUTERS