Principal Durgesh Mishra molested the girl in the school premises yesterday as there were lesser students in the classroom due to heavy rains in the region, said Station Officer Stayendra Kumar Yadav said.
The girl's parent informed the Basic Shiksha Adhikari (BSA) Satya Prakash Tripathi about the incident yesterday.
Based on the complaint lodged by the police, Mishra was arrested today from his residence, he said.
Upon BSA's inquiry, the principal has also been put under suspension, Yadav added.