The Thursday night attack recalled December's gang-rape and death of a 23-year-old student in a moving bus in New Delhi -- an assault that caused outrage throughout India.
In the latest attack, police said the woman, an intern for a magazine in Mumbai, was on assignment with a male colleague, also an intern, in a dilapidated section of south Mumbai, NDTV television channel reported.
Police said the two were confronted by the attackers who, after harassing them, beat and tied up the male intern. Later, the men dragged the woman into a rundown, abandoned building, where she was sexually assaulted.
The NDTV report said the attackers fled the scene after the woman became unconscious. After she regained consciousness, the two victims took a taxi to a nearby hospital, where they were able to provide a description of their attackers.
The woman was in stable condition at Jaslok Hospital.
Police said they arrested a suspect who confessed to the crime and had identified four others. All are reported to be in their 20s.
Mumbai Police Commissioner Satyapal Singh said he suspected the attackers were drug addicts who lived in the area.
In the New Delhi case, the student was assaulted by six men in a moving bus. Her male companion also was severely beaten. The woman's death two weeks later triggered massive nationwide protests for days. Laws relating to crimes against women have since been tightened.