A boil advisory has been issued for hundreds of city water customers along the Ohio River due to a water main break.

According to a notice from the city’s Water Treatment and Distribution Department, the notice applies to customers on Fourth Street from Greene to South Seventh Street and Hart, Wayne, Charles and South Sixth streets, and anyone in the nearby vicinity, who had low pressure or no pressure. An estimated 400 connections could be affected.

Customers who may have experienced a loss of water service or pressure are advised to rapid boil drinking water or water used in food preparation for two minutes following restoration of water service. The announcement says customers should flush their service lines using cold water lines only until the water is clear. Brown or cloudy water due to mineral deposits or air are normal discolorations after an interruption in service.

The advisory will remain in effect until customers are notified of its cancellation through local media.