The incident came to light last week when the parents of the 13-year-old victim, residing in Farsh Bazar in east Delhi, approached police and complained about the incident.
According to the complaint, the victim was kidnapped from near her house by the group of people, including one person whom she addresses as "uncle", on March 16 and forcibly taken to Loni in Ghaziabad.
"There were four known persons and four unknown persons in the room where she was taken. They raped her. The family brought the girl to police on April 12. After counselling her, a case of rape was registered," a senior police official said.
Of the eight persons, three were arrested -- Deepak (21) and Ranjeet (20), known to the victim, and Sohan Lal (24).
Police said they have identified the remaining three unknown persons and efforts are on to nab them along with two others.
The victim is undergoing treatment at Hedgewar Hospital in east Delhi. The girl's family alleged that police had refused to lodge their complaint.