An unidentified person whisked the girl, who was playing in a street, to a remote place and allegedly raped her after promising her some chocolates last night, DCP (East) Krishna Bhat told reporters.
The victim had come to her grandparents' house to celebrate New Year, he added.
After committing rape, the accused left the victim from where he picked her, DCP Bhat said.
The minor did not reveal the incident to her father the same night, but the crime came to light when the she was taken to Dr Ambedkar Hospital after she complained of stomach ache, DCP Bhat said. "The doctors confirmed of a rape case," he added.
Deverajeevanhalli police has filed an FIR and formed three teams to nab the culprit.