The victim, a class XI student, used to stay with her parents in the quarters inside the school campus, where her mother was an employee, Chakeri Police Station In Charge Rajiv said.
Krishna and Raj Kumar, fourth-class employees in the school, arrived at their room late last night, when the girl's father was not present, and sent her mother outside for some work, the police official said.
The duo then allegedly raped the girl and left the spot after threatening her not to disclose the incident to anyone, he said.
The victim and her mother then filed a complaint against the accused, leading to their arrest, the official said.
The girl has been sent for medical examination and the matter is being probed, he added.