Thrissur: Three classrooms and a stage at the Government UP School in Chaipankuzhy, Kodassery, Athirappilly, collapsed on Friday, with school authorities pointing to the ongoing hill highway works near the institution as a possible cause.

The school bus also sustained damage in the incident. No students were injured as the school was closed for a holiday.

The headmistress Bai P V told Onmanorama that construction work on the hill highway near the school has been ongoing since April.

"Earlier, as part of the construction, the school's compound wall was demolished, and we now don't have a compound wall. While classes were being held, students were made to sit in different classrooms farther away from where the work was taking place," she said.

The headmistress suspects that the collapse occurred after workers removed too much sand from underneath and around the school during the construction work.

"Till the collapse, we had not noticed any cracks or other flaws in the building. This happened all of a sudden," she said. She added that the excavation may have weakened the ground, causing the structure housing the stage and attached classrooms to collapse.

Meanwhile, PWD Assistant Engineer Shoba said the issue was not the removal of sand, but that the demolition of the compound wall may have affected the foundation of the school building.