The entire sixth form at Treorchy Comprehensive has been sent home after a case of coronavirus was confirmed at the school.
They have been told they can return to classes on Monday September 14 after the areas of the school are deep cleaned.
The rest of the school remains open.
Rhondda Cynon Taf has seen the most cases of coronavirus in schools in all parts of Wales, figures obtained by WalesOnline show. More details on that here
In a message on the school's website headteacher R Angell Jones says:"Treorchy Comprehensive School has been advised by Public Health Wales that there has been a confirmed case of COVID 19 within the school.
"As a precautionary measure and to enable us to deep clean some areas of the school, we have requested all pupils in Years 12 and 13 are to remain home on Friday 11th September 2020 only.
"All Year 12 and 13 pupils should return to school on Monday 14th September 2020 unless they have been directly contacted by the school or Track and Trace
"The school remains open for all other pupils and we will continue to be vigilant in adhering to all guidelines so that we can keep all children and staff safe."
Apart from the Treorchy case a total 36 pupils and staff in Wales had tested positive for Covid-19 in the first two weeks since schools returned up to September 10, figures obtained by WalesOnline show.
Public Health Wales confirmed that figure yesterday and said the 36 cases had been in 31 schools up to September 9.
RCT alone has seen 13 cases in schools so far - one pupil and 12 school-based staff - as the area has seen its rate of infections rise signficantly leaving it at risk of a locallockdown. See live updates on coronavirus in Wales here.
