Twelve new cases of coronavirus have been confirmed in England, the chief medical officer says.
It is the biggest jump in cases the UK has seen in one day.
Three patients caught the virus in the UK – they are known to be contacts of someone who already had it, and were found through contact-tracing, Professor Chris Whitty said.
One of the patients, from Essex, has not been abroad and it is not clear where they contracted COVID-19.
Six of the patients had recently travelled to Italy, and two had been to Iran.
The patients who have recently travelled are from London, West Yorkshire, Greater Manchester, Hertfordshire and Gloucestershire.
They join three cases reported yesterday, from Hertfordshire, Gloucestershire and Berkshire.
It brings the total number of confirmed cases in the UK to 35, including one in Wales and one in Northern Ireland.
Earlier, Health Secretary Matt Hancock said that in the event of a widespread outbreak in the UK, all options to contain the virus would be on the table, including banning large events and locking down cities.