Thousands of residents of a western Ohio community were told to stop drinking tap water after workers at a chemical treatment plant accidentally added toxic hydrochloric acid to the water supply.

No serious injuries were reported.

Forty pounds of the acid were added to Bellaire's water Sunday. The mistake was discovered Monday morning when workers noticed fluoride levels were lower than normal.

Water department superintendent Kirk Baker says a water supplier inadvertently gave plant workers hydrochloric acid instead of fluoride. Baker says crews opened fire hydrants and drained the entire water system to clean it.

The water was deemed safe at about 12:30 p.m.

Customers were urged to avoid using tap water and Bellaire High School dismissed classes early.

About 2,400 people were affected by the contamination.