Authorities on Thursday expanded an existing border-area ocean-pollution alert north to include Silver Strand State Beach.
The warning initially was issued after recent storms caused rain-driven sewage to enter the United States from Baja California via the Tijuana River, according to the San Diego County Department of Environmental Health.
On Wednesday, officials extended the scope of the advisory into Imperial Beach.
Signs cautioning of contamination hazards will stand along all the affected beaches until follow-up testing deems them safe again for recreational uses.
