Angry residents suspecting the involvement of three local youths, one of them the husband of a friend of the girl, who were employed as guards at an under-construction nursing home in the vicinity beat them up severely, police said.
They were rescued by Trinamool Congress workers, who locked the three inside the party office before handing them over to the police.
The locals gheraoed the police station demanding their punishment and blocked the arterial BC Road for sometime.
In another incident, a 19-year old medical attendant in a private hospital in Rajarhat area in North 24 Parganas, took a shuttle car from her place of work on Sunday to Bidhannagar railway station in the northern area of the city.
The shuttle car was carrying another passenger apart from the driver, police said.
The teenager alleged that she became unconscious inside the car. When she gained consciousness, she found herself in a room in Sonagachi, a red light area, where she was allegedly raped by the driver in the presence of two other youths.
She later managed to escape from the area and took a taxi to Cossipore police station where she filed a police complaint.
"A medical examination has been conducted on the teenage girl. We have started an investigation," Joint CP (Crime) Pallab Kanti Ghosh said.