Superintendent of Police Shankar Yadav identified the offending teacher as Dev Kumar and said police were investigating.
The incident took place at the Sanatan Dharm Inter-College when the teacher dragged away three students who he felt were creating a nuisance at a prayer meeting.
He allegedly thrashed them with a cane, and refused to let them go even after one of them pleaded that he was in pain.
Hundreds of students then revolted, and freed the three students. Doctors at a hospital said one of them, Arun Raghav, had a fracture in his arm.
This led to massive street protest, with students jamming traffic and demanding the teacher's arrest.
The injured students were identified as Rajan Singh, a student of Class XI, and Raghav and Shahzad of Class XII.
School principal M.C. Gupta said he too was conducting an inquiry.