Two cars were damaged when a skip caught fire at San Andrea School in Imselliet, limits of Mġarr on Wednesday morning.
No one was injured, eyewitnesses told Times of Malta.
San Andrea schoolchildren are still on holiday. They return to school on Thursday.
Head of school Stefania Bartolo said the fire was quickly contained by an exceptional team of some of the school's staff using the school's fire prevention measures, training and materials, until Civil Protection Department officers arrived.
Ms Bartolo reassured parents and guardians that there was no danger whatsoever and that school staff received intensive fire and emergency training.
Parents of students at neighbouring San Anton school were also reassured separately by that school's administration.
San Anton students returned back to school on Tuesday but were unaffected by the fire, the school administration said in a note to parents.
"Our school was in no way affected by this incident, we only closed the windows due to some smoke which reached us for a couple of minutes," the school told parents.