"The four accused, aged between 20-23, were arrested after their interrogation on Wednesday," Banaswadi Circle Inspector D.H. Munikrishna told IANS here.
The accused are said to be residents of the area (Kammanahalli) in the city's north-east suburb where the victim was molested and groped in the wee hours (2.41 a.m.) of Sunday by two of them when she was returning home with her friend after returning from a New Year's party.
The horrifying incident came to light on Tuesday night when a resident of the area gave the police video footage captured by a CCTV camera he had installed at his house.
"Our senior officials will give the case details after producing the accused in a local court for police custody for further interrogation and identification by the victim, who has been contacted by our police women," said Munikrishna.
An FIR was filed suo moto against the culprits under sections 341 (wrongful restraint) and 354A and 354B (assault or criminal force on woman with intent to outrage her modesty) of the Indian Penal Code.
The footage showed the victim walking in the close residential area towards her rented accommodation and the scooter-borne duo turning around and one of them walking across to her.
The duo was then seen molesting and dragging her to the two-wheeler, even as she tried to wriggle out, slapping the molester.
The video clip also showed the victim falling on the road after escaping from her attackers even as some onlookers watched "the horror" from a distance.