The incident took place yesterday when the girl, a resident of Vangani town, was walking towards public toilet, police said.
The girl was waylaid by Vijay Wagri, who molested her, they said.
When she resisted, two other youths came and held her back, while Wagri continued to molest her, police said.
A case was registered by the police under relevant sections of IPC, they said, adding efforts are on to nab the trio.