The boy, a neighbour of the 12-year-old girl, took her upstairs the building in the district's Nagaram village late last night and allegedly committed the offence, they said based on a complaint lodged by the victim's parents.
Following the complaint, Nizamabad V Town police booked a case against the teenaged boy under relevant sections of the IPC and Protection of Children from Sexual Offences Act.
The victim has been sent for medical examination, they said, adding that efforts were on to nab the accused.