A Gwynedd school had to temporarily stop some classes due to “staff illness”.
Gwynedd Council is now working with Ysgol Pendalar, a special education school in Caernarfon, on a contingency plan to prevent further disruption.
It followed speculation the school was having to shut classrooms due to a shortage of teaching assistants.
A council spokesperson said: “We are aware staff illness at Ysgol Pendalar has resulted in some classes being closed for a short time.
“We understand the frustration and upset this may cause pupils and their families and we are working with the school on a contingency plan to prevent further disruption to lessons.”
The education sector has reported a national shortage of classroom assistants across Wales.