The Public Health Agency (PHA) has identified a small number of probable cases of the Delta variant (VOC-21APR-02, first detected in India) in the Kilkeel area.
These early results are suggestive of the variant but this has not been confirmed.
As a precautionary measure the PHA is asking asymptomatic people to get tested in selected, targeted neighbourhoods within the in the Kilkeel area.
A spokesperson for the PHA said, "This is in advance of confirmation of whether a variant is present so that we can identify asymptomatic COVID-19 cases early and reduce the risk of spread in the community.
"Testing is opening to everyone in these areas over the age of five-years-old. Households in the areas that this testing covers will be contacted directly by PHA in the coming days."
Dr Stephen Bergin, Interim Director of Public Health at the PHA, said: “This testing in the Kilkeel area is a precautionary measure to identify asymptomatic cases and prevent community spread.
“We encourage all those eligible in the neighbourhoods identified by the agency to present for testing. This is a reminder to everyone through Northern Ireland to continue to carry out all public health measures to help stop the spread of COVID-19.
"Continue with good hand and respiratory hygiene, keep your distance of two metres from others where possible, wear a face covering where necessary, keep rooms well ventilated, and if you’re offered the vaccine, book your appointment. Stopping the spread of the virus will help save lives.”
Mobile test unit locations for asymptomatic testing are at Kilkeel Leisure Centre, St. Louis Grammar School, and Ballymartin GAC car park.