Two Scottish schools have been hit by suspected outbreaks of the norovirus sickness bug.

Some pupils at St Modan's High School in Stirling and Cockenzie Primary School in East Lothian have experienced vomiting and diarrhoea, symptoms of the highly contagious virus known as the winter vomiting bug.

Forty-five children and two staff members are understood to have been off with the bug since the symptoms at the primary school first emerged on Wednesday.

Local reports in Stirling suggested that more than 100 pupils were hit at St Modan's but health officials have not commented on the numbers affected.

Both schools, which are being deep cleaned in places, remained open as usual.

A spokeswoman for NHS Forth Valley said: "Following an outbreak of diarrhoea and vomiting at St Modan's High School in Stirling, extensive deep cleaning at the school will continue throughout this weekend.

"Many pupils have chosen to stay away from school but with a near-full complement of staff, lessons are continuing as normal.

"Any pupil who feels unwell should be kept away from school and those who have been ill should not return until 48 hours after symptoms disappear."

She added: "Diarrhoea and vomiting is a common, self-limiting illness with many cases currently affecting the community at large; it was therefore felt appropriate that the school should remain open."

Professor Alison McCallum, director of public health and health policy at NHS Lothian, said: "We are monitoring cases of norovirus circulating in the wider community, including a suspected outbreak at Cockenzie Primary School.

"The Health Protection Team at NHS Lothian have issued letters to parents with information and advice and are keeping in regular contact with the school, which remains open as normal."

The health boards advise that frequent and thorough hand-washing, along with disinfecting surfaces, can help reduce the spread of infection.