Indian police are bracing themselves for more protests after a 23-year-old woman who was gang raped on a bus in New Delhi died in a Singapore hospital.
The attack, in which the medical student was savagely beaten and raped for almost an hour before being thrown out of the moving vehicle, sparked demonstrations across India.
Her uncle said: "This is a very sad day. And a very very sad happening. My condolences are with my niece's family. We want those arrested for this crime to be given the strictest possible sentence, and this has to be time bound."
The chief executive of the Mount Elizabeth Hospital in Singapore, where she was flown for specialist treatment on Thursday, said she had suffered severe organ failure.
Kelvin Loh added: "Her family and officials from the High Commission of India were by her side.
"Despite all efforts by a team of eight specialists ... to keep her stable, her condition continued to deteriorate over these two days. She had suffered from severe organ failure following serious injuries to her body and brain.
"She was courageous in fighting for her life for so long against the odds but the trauma to her body was too severe for her to overcome."
Crowds of protesters have gathered in New Delhi city centre for a sit-in, demanding political change to protect women from violence.
The area is home to the president's palace, the prime minister's office and key defence, foreign affairs and home ministries.
Authorities fear a repeat of demonstrations a week ago , where police fired tear gas and water cannon at activists.
But Daily Telegraph journalist Rahul Bedi, who is in New Delhi, said protesters were likely to remain peaceful to "avoid giving the politicians a tool" to criticise them.
"I think there's a conscious decision on the part of the protesters in the land of Gandhi to protest in a non-violent way," he added.
"These sit-ins are going to continue for a long time. This crime has shocked the country, rape is something this country has been dancing around for the last 30 or 40 years."
The Indian High Commissioner to Singapore told reporters a chartered aircraft would fly the victim's body back to India on Saturday, along with members of her family.
Indian Prime Minister Manmohan Singh said he was deeply saddened by the woman's death and described the reaction to the case as "perfectly understandable from a young India and an India that genuinely desires change".
"It would be a true homage to her memory if we are able to channel these emotions and energies into a constructive course of action," he added.
Police have arrested six men over the attack, which happened two weeks ago as the woman was travelling home on a bus with a male friend after a trip to the cinema.
According to media reports, six men on the bus beat them with metal rods and repeatedly raped the woman. Her male companion survived the assault.
The case triggered nationwide protests which culminated last weekend in clashes with police in the Indian capital.
Indian authorities have been accused of belittling rape victims and refusing to punish their attackers.
In a separate case, a 17-year-old Indian girl who was allegedly gang raped has killed herself after police pressured her to drop the case and marry one of her attackers.
The deaths come after it emerged the names, addresses and photographs of convicted rapists will be posted online by Indian police to publicly shame them for their crimes.