Video report by ITV News Health Correspondent Emily Morgan
A GP surgery in Brighton has temporarily closed after a doctor at the practice contracted coronavirus.
The County Oak Medical Centre, in Caden Hill, says on its answerphone message it has been forced to close because of "an urgent operational health and safety reason".
Footage from the practice shows individuals in full protective suits and face masks appearing to disinfect the inside of the centre.
Four more patients in England tested positive for the viral pneumonia on Monday - all known contacts of a businessman who was diagnosed in Brighton last week. Public Health England says two of these cases are healthcare workers.
It's understood all new cases can be traced back to one so-called "super-spreader", a businessman who picked up the virus in Singapore.
Public Health England Medical Director Yvonne Doyle said: "As a result of our contact tracing we now know the new cases announced today are all closely linked to one another.
"Our priority has been to speak to those who have close and sustained contact with confirmed cases, so we can advise them on what they can do to limit the spread of the virus.
"Two of these new cases are healthcare workers and as soon as they were identified, we advised them to self-isolate in order to keep patient contact to a minimum.
"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 World Health Organisation described the "onward transmission" between UK cases as "concerning", adding:
"The detection of this small number of cases could be the spark that becomes a bigger fire."
Signs on the doors of the County Oak Medical Centre advise patients to "stop" and not enter if they believe they have come into contact with someone who has the coronavirus.
ITV News Health Correspondent Emily Morgan with the latest on the coronavirus situation in the UK
The Brighton businessman with links to multiple other cases had attended a conference in Singapore last month.
He stopped at a ski resort in the French alps on his way back to the UK, before flying into Gatwick on January 28.
He was checked positive for coronavirus upon his return to Brighton and was transferred to an infectious diseases unit on 6 February.
Today the government announced it was introducing new powers to forcibly quarantine those with the virus.
The PA news agency understands the decision was in response to one of the Britons who returned from Wuhan attempting to leave isolation.
A Government source said "there was someone who was threatening to abscond from Arrowe Park" - the quarantine facility in Merseyside where Britons repatriated from Wuhan, the epicentre of the virus, are staying.
Information on the Department of Health website says Health Secretary Matt Hancock has introduced the new measures in light of the "public health emergency" from coronavirus.
The death toll from the outbreak - which originated from Wuhan in China - reached 908 on Monday morning.
All but two of the deaths have taken place in mainland China where the number of confirmed cases has also increased to 40,171.
In Japan, a second British national is among 130 confirmed coronavirus cases on board a quarantined cruise ship off the coast of Yokohama.