Police said the accused were found under the influence of alcohol. They allegedly forced themselves on her and threatened her of dire consequences if she revealed about the incident to anyone, PTI quoted a police official as saying.
Victim's mother filed a police complaint after the girl told her about the incident.
When the girl's mother returned from work, the victim narrated her ordeal to her mother, who took her to the police station, he said.
A case was registered under the relevant sections of POCSO (Prevention of Children from Sexual offences) and IPC. The accused were arrested on the same day.
The victim stays in a shanty in Kalyan Vaas while the four accused stay in east Vinod Nagar.
The landlord's son is aged 28 and is married. One of the accused is a 19-year-old, who does the job of washing cars. Two of the accused are in their 30s, the officer said.
(With inputs from PTI)