A number of pupils and staff at Prestatyn High School have been told to self-isolate following a confirmed case at the school.
A total of six people have been asked to self-isolate until October 7 to try and reduce the possible spread of Covid-19, in line with Public Health Wales guidance.
A statement from Denbighshire council said:
"The school has written to all parents and guardians today (Friday) informing them of the position.
"Parents/guardians have been advised to remain alert for the main symptoms of coronavirus such as 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.
"A test can be booked by phoning 119 or online here.
"Advice requires those self-isolating to stay at home, not to go outdoors to exercise, to visit shops, family or friends, or to other public spaces.
"Please do not invite people to your house.
"If children and staff remain well, they can return to school on October 8."
"Councillor Huw Hilditch-Roberts, cabinet Lead Member for Education, Children, Young People and Public Engagement, said:
“We would like to reassure parents that stringent track, trace and protect measures are in place within all our schools.
“We continue to work closely with the school, Public Health Wales as well as NHS Wales Test, Trace and Protect to ensure that appropriate measures are in place to protect pupils, staff and the wider community.
“We are urging parents and guardians to remain vigilant and to request a test if their child presents any symptoms.”
Further formation on Test, Trace, Protect can be found here.