MUMBAI - Five men gang-raped a woman photographer in India's financial hub Mumbai, police said Friday, fuelling protests and stirring memories of a similar attack last December in New Delhi.

The attack took place on Thursday evening in an upmarket district of central Mumbai as the 23-year-old woman and a male colleague were taking photos of old buildings for a magazine.

The pair were approached by members of the gang and told they should not be there. The man was then tied up with a belt while the woman was raped repeatedly nearby, Mumbai's police commissioner Satyapal Singh told reporters.

"It is a shameful and extremely disturbing event," he said.

One man in his early 20s has been arrested while the hunt is on for his four alleged accomplices, who have been identified by police. Sketches of the accused have been released. The victim, reportedly an intern, is undergoing treatment at Mumbai's Jaslok Hospital and preliminary reports suggest multiple internal injuries, a police officer told AFP. A hospital statement said she was "stable".

The attack, which shocked a city seen as far safer for women than the capital, happened in an abandoned mill compound next to an area of upscale apartment blocks, shops and restaurants.

On Friday, police stood watch in forested patches while others walked through overgrown grass around the cordoned-off crime scene, where greenery has crept over the walls of the derelict structure.

"We are 100 percent confident of cracking the case," Singh said, adding that 20 police teams have been formed as part of the investigation.

"We will gather all the clinching evidence and aim to get the maximum punishment, which we hope will be done through a fast-track court." The incident comes eight months after another 23-year-old woman was gang-raped by five men in a moving bus in New Delhi, while her male companion was beaten up. She died two weeks later from severe injuries.

A trial is in in its final stages in that case, which sparked massive protests and led to a tougher anti-rape law. The new measures increased punishment for sex offenders, which now include the death penalty if a victim dies, and broadened the definition of sexual assault.

Sex crimes have continued across India since the December 16 gang-rape, and Thursday's attack once again captured the attention of the media and public.

"Women need to be vigilant and aware of themselves and the surroundings. There is no solution, no cure," Swati Pillai, who works in south Mumbai with an advertising firm, told AFP.

Business manager and mother Manjiri Jamadagni said the incident was "very disturbing". "Bombay was always safe but in recent years it's been changing. It's not the same," she said, using Mumbai's former name.

The city council came under fire in May for a proposal to ban lingerie-clad mannequin dummies in shops and markets for fear they could encourage sex crime. Thursday's attack sparked anger on social media websites, and journalist groups protested in Mumbai on Friday afternoon, with many holding signs which read "Mumbai: India's New Rape Capital" and "Bring Rapists To Book!".

India's parliament in New Delhi also erupted in anger.  India's Law Minister Kapil Sibal said sex assaults must be dealt with "in the most severe fashion". "This country cannot afford to have our women (and) children insecure in the hands of those who attack them," he told reporters.