Beijing  - Carbolic acid spilled into a river from a chemical plant and forced the suspension of tap water supplies to more than 1 million people in the eastern Chinese city of Yancheng on Saturday, state media reported.

Officials shut down the Biaoxin Chemical Company and police detained the owners for questioning after the acid polluted two of the three water plants in the city of 1.5 million on Friday, the official Xinhua news agency said.

The privately owned Biaoxin had illegally discharged waste water into the Mangshe river, the agency quoted Xue Yu, secretary of the the city government, as saying.

Workers noticed an unusual smell at the two water plants early Friday and tests confirmed the presence of carbolic acid, or phenol, making the water unfit for drinking, the agency said. (dpa)