LUCHENG - Four people directly responsible for a chemical leakage incident that contaminated rivers in north China's Shanxi Province have been dismissed, local authorities said Sunday.

Chen Jianwen, Tianji Coal Chemical Industry Group general manager, Ren Yongjie, the group's deputy manager who is in charge of work safety, and two heads of the plant's storage workshop were sacked, said Liu Dashan, Shanxi provincial environmental bureau's chief engineer.

Aniline had leaked from a broken pipe at the plant in Lucheng City.

An initial investigation revealed that a loose drainage valve in the plant, which is owned by the group, was blamed for the leak of nearly 9 tonnes of aniline.

Plant employees spotted the leak on the morning of December 31, while conducting a routine check.

As of Sunday, aniline in a local river has affected the drainage area of about 80 square kilometers and 28 villages in Shanxi.

The contamination incident has also affected tap water in downstream cities in neighboring Hebei and Henan provinces.