Five hundred and seventy pupils have been told to self-isolate following cases of coronavirus at three Denbighshire schools.
On Saturday Denbighshire council confirmed 240 Yr 9 pupils at Rhyl High School, 240 Yr 9 pupils at Ysgol Glan Clwyd in St Asaph and 90 Yr 3 pupils at Ysgol Llywelyn in Rhyl have been told to self-isolate until October 15 following one confirmed case of COVID-19 at each school.
Six members of staff at Ysgol Llywelyn have also been told to self-isolate, until 15 October.
One member of staff at Ysgol Glan Clwyd and a school bus route have been told to self-isolate until 15 October.
Denbighshire council say the schools remain open and the council is working closely with the schools affected together with Public Health Wales and the NHS Wales Test, Trace and Protect to ensure appropriate measures are in place to protect pupils, staff and the wider community.
Letters were sent to parents and guardians on Saturday informing them of the position.
Parents/ guardians have been advised to remain alert for the main symptoms of coronavirus: a new or continuous cough; a high temperature; and a loss of or change to sense of smell or taste.
Those advised to self-isolated should book a coronavirus test if they develop any of these symptoms, even if they are mild.
Advice requires those self-isolating to stay at home, not to go outdoors to exercise, not to visit shops, family or friends, or to other public spaces and not to invite people to their houses.
A test can be booked by phoning 119 or online here.
Further formation on Test, Trace, Protect can be found here.