The accused were arrested from their homes and slapped with charges under IPC and POCSO Acts.
In her complaint, the girl told police that her friend took her to the school on the pretext of job yesterday.
They went to an office room inside the school premises where her friend, who is a scrap dealer, and the private school's security guard raped her, a senior police official said.
The prime accused, who was known to the girl for at least a year, met the girl at a local market yesterday and told her that he had set an appointment with someone at the private school.
