BEIJING (AP) — Residents in a northern Chinese city are without water after the local government cut off the supply because of industrial chemicals that contaminated a river.

The Handan city government in Hebei province says it cut off the water Saturday afternoon after an accident in neighboring Shanxi province caused pollutants to pour into a river. It didn’t say how many residents were affected. The population of the city and its rural areas is 9 million.

Xinhua News Agency said Sunday that a loose drainage valve in a chemical plant was to blame for the leaking of nearly 9 tons of the chemical aniline into the river. It said another 30 tons of aniline have been contained in a disused reservoir.

Aniline, used in manufacturing polyurethane, can be toxic to humans.