In an email to parents, the school confirmed the victim was a pupil and said it “went into full lockdown, with all children staying in their classroom with their teacher”.
The school announced it would close at 13:00, and students began to emerge about a few minutes later.
Sixteen-year-old Letizia was in a maths class when it was decided everyone should barricade the classroom door.
“I thought at first it could be a drill, but then we started locking everything and I saw the teachers walking through the corridors,” she said.
“Everyone then started to panic.”