Shropshire Council today said that 21 residents at the Craven Arms site have now tested positive for Covid-19. The outbreak has been linked to a similar outbreak at the Leighton Arches traveller site in Welshpool.
The council said 41 people have been tested overall and contact tracing is being carried out.
The authority also said it had delivered essential items including food, prescriptions, and fuel to the site, and had also closed a playground and outdoor gym on Newington Way.
In a statement the council said: "As of today, 21 positive cases on the site have been confirmed.
"Offers of testing to all residents at the site continue, as we expect to see the number of positive cases rise in the coming days, before infection control measures and social distancing start to take effect.
More Covid-19 coverage:
"All residents on the caravan site have been asked to self-isolate with members of their households for 14 days following contact with a positive case.
"Those residents who had tested positive for coronavirus were asked to self-isolate for a minimum seven days from the time they started showing symptoms or from when they took their test. If those who have been in self-isolation for the minimum seven days are now well enough, they can finish self-isolation and leave their home. This means that initial positive cases will finish isolation this coming week."
As a result of the outbreak a test site has been set up in Craven Arms, at the town's business park. It will be open for the next two weeks, every day from 10.30am-3.30pm.
Testing is by appointment only, and people can book slots using NHS Test and Trace online or by ringing 119.
Councillor David Evans said: “Our priority is to protect the health and wellbeing of our local residents. I’ve been in Craven Arms today to talk to residents and businesses to answer any questions and reassure them that the risk to the general public is low.
“We continue to work closely with Shropshire Council’s partners including the NHS, Public Health England, our local police and other key agencies, to provide up to date advice and support to our local community, to help prevent further spread of coronavirus.
“I would like to thank members of the community for their own ongoing support and co-operation.
“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.
“As we now have a test site in the town, if anyone is having symptoms, I would strongly encourage them to book an appointment either online or by calling 119. Anyone concerned can book an appointment.”