England's chief medical officer has warned that schools could potentially close for two months or more in the UK if the spread of coronavirus intensifies.

Professor Chris Whitty warned that onward transmission between people who had not been to a coronavirus hotspot was "just a matter of time in my view".

His comments came as two more people in England were diagnosed with Covid-19, taking the UK total to 15 cases. The first two confirmed cases were in York.

Speaking at a Nuffield Trust summit in London, Prof Whitty said: "If this becomes a global epidemic, then the UK will get it, and if it does not become a global epidemic, the UK is perfectly capable of containing and getting rid of individual cases leading to onward transmission."

But he said onward transmission was "just a matter of time in my view", adding: "If it is something which is containable, the UK can contain it. If it is not containable, it will be non-containable everywhere and then it is coming our way."

He said there could be a potential "social cost" if the virus intensifies which could include actions such as reducing mass gatherings and closing schools.

He said he was not saying that would happen, but that the effectiveness of such strategies would have to be weighed up against social cost.

"One of the things that's really clear with this virus, much more so than flu, is that anything we do we're going to have to do for quite a long period of time, probably more than two months," he said.

"The implications of that are non-trivial, so we need to think that through carefully.

"This is something we face as really quite a serious problem for society potentially if this goes out of control.

"It may not, but if it does globally then we may have to face that."

One of the new UK cases on Thursday - a parent at a Buxton primary school in Derbyshire - contracted the virus in Tenerife, where 168 Britons have been confined to a hotel on the south-west of the island.

The other person contracted the virus in Italy, which has become the worst affected country in Europe with more than 400 cases and 14 deaths.