Four more people have tested positive for coronavirus in England, health officials have said.
It means that 40 people have now been diagnosed with Covid–19 in the UK.
In a statement on Monday, chief medical officer Professor Chris Whitty said that all four patients had recently travelled from Italy, where more than 1,700 cases of coronavirus have been detected.
The patients – who are from Hertfordshire, Devon and Kent – are all being investigated and contact tracing has begun, Whitty added.
The latest news comes after it was revealed that one of the patients who tested positive over the weekend was a health worker at a cancer centre in Middlesex.
But NHS officials at Mount Vernon Cancer Centre said the risk to patients and staff was “very low” and that the centre remained open.
Another case was confirmed at the North East London NHS Foundation Trust offices in Kent.
Vinters Business Park – home to Maidstone Studios and an office suite used by the trust – confirmed that a tenant had tested positive for the virus and their team “is taking the sensible precaution of self-isolating and working from home”.
Meanwhile, travel firm Tui said 17 of its customers at a quarantined hotel in Tenerife have been flown back to the UK after testing negative for coronavirus.
A Tui spokeswoman said its British guests at the H10 Costa Adeje Palace returned on two separate flights to Bristol and Newcastle on Sunday night.
The company’s remaining 19 holidaymakers will be flown home on Tuesday, subject to their test results, she said.
More than 13,500 people have now been tested for coronavirus in the UK.
Prime minister Boris Johnson has said there is “little doubt” the virus will present a “significant challenge” for the UK.
Meanwhile, health secretary Matt Hancock refused to rule out British cities on lockdown to prevent the spread of the infection.
He told the BBC’s Andrew Marr programme: “There is clearly a huge economic and social downside to (shutting down cities).
“But we don’t take anything off the table at this stage because you have to make sure you have all the tools available if that is what is necessary.”