Residents of Uster, the third-largest city in the canton of Zurich, are being warned about bacteriologically contaminated drinking water.

The contamination affects the areas of Riedikon, Niederuster, Werrikon, and Nänikon.

Local authorities advise against using tap water for drinking, cooking, or cleaning food-related items.

Instead, residents should boil water before use or opt for bottled mineral water.

The cause of the contamination remains unknown, but Energie Uster is working urgently to restore safe water supply.

Further updates are expected on Friday.