Visitor are being asked to stay away from a West country hospital which has had to close wards because of a stomach virus.

And a similar bug has spread to a North Yorkshire hospital which has closed two wards following an outbreak.

Staff at Scarborough Hospital noticed some patients showing symptoms of the Norwalk virus on Monday.

The bug, also known as the winter vomiting virus, causes diarrhoea and vomiting but is not fatal.

In Plymouth, the worst-affected area, visitors are being asked to stay away from Derriford Hospital for fear of spreading the virus further.

Quick response

Almost 350 patients and staff at Derriford have been affected by the bug as well as patients at hospitals in Torbay and Truro.

In Scarborough, 11 women have shown signs of the bug but no staff have been taken ill.

Gilly Collinson, a spokeswoman for Scarborough Hospital, said infection control teams were at work and were advising visitors on what measures to take.

Although test results will not be available till Wednesday, the virus is "very likely" to be Norwalk.

"Yesterday our staff on Duchess ward identified that there were some patients poorly.

"They responded to this very quickly and it does seem that they may be affected by the Norwalk virus which is so prevalent nationally at the moment."

She added that some patients on Graham ward also showed similar symptoms, although these are now not thought to be caused by the virus.

Nonetheless, the ward has been closed to new admissions.

"We have been supercautious," she added.

Each ward can accommodate 30 general medical patients.