The nor'wester took place last night and the storm during it broke off a huge branch, which crashed on the residential school for tribal students at Vejangiwada area.
While most of the injured students were discharged after preliminary treatment at a nearby hospital, three of them were admitted to Kalimela hospital where they were reported to be in stable condition, inspector in-Charge of Kalimela police station, R P Nag said.
District Education Officer P K Mohapatra said some structures of the school building has been damaged in the storm and a detailed assessment is on.