A second GP surgery branch in Brighton has been shut following the outbreak of coronavirus in the area.
County Oak Medical Centre in Brighton closed on Monday, due to "an urgent operational health and safety reason".
It emerged on Tuesday morning that a second branch of the surgery, less than two miles away, has also been closed - a sign on the door of the Deneway branch cites "organisational health and safety reasons".
Officials are working to trace patients of two healthcare workers who are among eight people in the UK to be diagnosed with viral pneumonia.
County Oak Medical Centre in Brighton is cleaned by officials in full protective suits:
Speaking about the four latest British cases, World Health Organisation director general Tedros Adhanom Ghebreyesus said they were "concerning instances of onward transmission from people with no travel history to China".
He warned such spread "could be the spark that becomes a bigger fire", and warned countries to work to contain the virus "to prevent a bigger fire".
In a statement on Monday, Public Health England medical director Yvonne Doyle said:
"We are now working urgently to identify all patients and other healthcare workers who may have come into close contact, and at this stage we believe this to be a relatively small number."
The Guardian reported that the four new cases are three men, one of whom is a doctor, and one woman.
The four new cases are now being treated at specialist infection centres at St Thomas’ and the Royal Free hospitals in London.
People wearing protective full body suits and gloves were seen cleaning County Oak Medical Centre on Monday.
The pharmacy at County Oak Medical Centre will reopen on Tuesday, staff confirmed, but the surgery is expected to remain closed.
Speaking to the PA news agency on Tuesday outside County Oak Medical Centre where she is a patient, a 43-year-old from Brighton said: "I was here on the 3rd and the 5th and they will not tell me the risk even though I am immunosuppressed with lupus."
The mother-of-four said she has called 111 several times but was told "the risk isn't known" and to stay in for 14 days if she feels at risk.
Professor Martin Marshall, Chair of the Royal College of GPs, said: "Patients should not be alarmed as it is still more likely that anyone with flu-like symptoms will have the flu.
"However, in light of the members of staff who tested positive for coronavirus in Brighton we’d like to remind the public that it is vital that any patient who thinks they may have symptoms does not try to attend a GP appointment or hospital emergency departments in person.
"They should stay at home and call NHS 111."
A sign on the door of both Brighton medical practices reiterates the same advice.
The four new UK cases were announced as the Government declared coronavirus a "serious and imminent threat to public health".
Announcing new legal powers on Monday, the Department of Health said people with coronavirus can now be forcibly quarantined, and can be forcibly sent into isolation if they pose a threat.
The PA news agency understands that the decision was in response to one of the Britons who returned from Wuhan in China, the source of the coronavirus outbreak, attempting to leave isolation at Arrowe Park Hospital on Merseyside.
Officials stressed that the risk to the public has not changed.
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Researchers in China have said the virus can have an incubation period of up to 24 days.
British Airways became the latest airline to extend its suspension of flights serving Beijing and Shanghai.
The latest developments come as health authorities confirm one of the hundreds of people recently evacuated from China to US military bases has the virus, with the person joining 13 confirmed cases across the country.