The police questioned four persons today in connection with the incident, the police said.
Alleging that Pushpa Thakur, class two student of Burnpur Girls School, was sexually assaulted and killed, locals protested, ransacked the school and threw stones on policemen which lathicharged the mob.
The post-mortem report would reveal whether the girl was raped, the sources said.
Pushpa had gone missing after she gave her examination in the school Tuesday morning. Her body with the throat slit was found yesterday.