BEIJING (AFP) - Three people were killed and another three wounded in an explosion at a chemical plant in east China on Tuesday, the official Xinhua news agency reported. The cause of the explosion at the privately owned plant in Leping city, Jiangxi province, is not yet known and no leaks of liquid or toxic gas were detected, Xinhua said, citing the city government. The Jiangwei High Technology Co., which was previously state-owned, produces nontoxic polyvinyl alcohol, which is commonly used in the manufacture of glue and acetic acid, a food additive that can be corrosive when concentrated.