Based on the victim's complaint, the police managed to track down the four culprits and arrested them from Kurla and the adjoining Vikhroli suburb.
They have been identified as Sonu Tiwari, Nilesh Baraskar, Shrikant Bhogle and Sidharth Wagh, and have been sent to police custody, said an officer of Nehru Nagar police station.
The incident occurred at around 11 p.m. on Monday when the woman was proceeding from Kurla station to the Lokmanya Tilak Terminus (LLT) to catch a train to Katni in Madhya Pradesh.
On a bridge outside the station, she sought directions to LTT from a passerby and even followed him near the railway line.
At one point, the woman stopped to relieve herself in some bushes when the passerby ahead of her suddenly disappeared.
The misfortune befell the woman when two drug-addicts hiding to consume drugs pounced on her, attacked her and raped her.
Two other persons who were going on a motorcycle stopped there, caught the women and had unnatural sex with her before speeding off.
They also robbed the victim of Rs 3,000 cash and a 'mangalsutra' worth nearly Rs 25,000, the police said. The victim is said to be a widow with two minor children and lives in Katni.
As she walked on the road towards LTT, she met a woman who helped her contact the local police, and later assisted her in identifying one of the accused as a local Kurla resident.
After the victim's medical test, police teams swung into action, fanned out in different areas during the night to round up all the accused and booked them for assault, robbery, rape, unnatural sex etc.
( With inputs from IANS )