Pupils at a Glasgow secondary school are among eight people to have tested positive in a coronavirus cluster in the city.
NHS officials said the pupils at Bannerman High School in Baillieston all tested positive before the school returned on Wednesday morning.
A further three positive cases had been identified in north east Glasgow by the NHS Greater Glasgow and Clyde (NHSGGC) test and protect service.
The health board also said the cases were not "causing any clinical concern".
All eight of the cases are said to be only experiencing mild symptoms.
"None of the cases are experiencing anything but mild symptoms and to maintain patient confidentiality we are unable to give any further information on the cases".
They were said to be working closely with the school and a number of other local businesses to trace any close contacts of the eight confirmed cases.
They are all now self-isolating at home, and none have actually attended school.
Dr de Caestecker added: "All settings that these cases attended during their infectious period are being identified, assessed and are being supported with control measures, and anyone who may have been exposed to these cases is being given appropriate advice".
"Anyone affected will be contacted through the Test and Protect service".
On Thursday they added there was "no indication any transmission has occurred in the school" and none of those affected returned to classes as the school reopened.
"I will continue to work with the education authorities and the health board to ensure this situation is managed and that parents can have confidence in sending their children to school". School staff, young people & families need assurances that their safety is a priority.