Twenty-one people have tested positive for coronavirus at a caravan park site in Shropshire, with health experts warning the number will rise.
A testing site has now been set up at a nearby business park, Shropshire Council and Public Health England said.
All residents have been told to self-isolate with their families.
To date 41 people at the residential site have been tested.
Contact tracing is being undertaken, and the number of positive cases is expected to increase before infection control measures and social distancing start to take effect, the council said.
Those who tested positive were asked to isolate for a minimum of seven days from the time they started showing symptoms, or from when they took their test.
People who were in contact with a positive case were told to isolate for 14 days, the council said.
A playground and outdoor gym on nearby Newington Way has been temporarily closed to help stop transmission, and the council said it had been arranging the delivery of food, prescriptions and essential supplies for residents.
David Evans, councillor for Church Stretton and Craven Arms, said teams were working with the NHS, Public Health England, police and other key agencies to provide advice and support to the local community.
"I would like to thank members of the community for their own ongoing support and co-operation," he said.
"We continue to rely on everyone at the site playing their part, and want to encourage the residents to continue to self-isolate and take all the necessary precautions.
"This is the only way we can help stop the spread of the virus."
Officials will monitor people's symptoms on a daily basis, and PPE, hand sanitisers and cleaning products have also been distributed on site.