About 25 to 30 students of the madrassa were standing on the roof of the old well when it suddenly caved in, killing three girls and injuring eight others in Pishtakara Bala area, police said.
The deceased and injured girls were between 10 to 16 age group.
Soon after the incident, the locals rushed to the scene to rescue the children who fell into the well.
The injured have been admitted to a hospital.