A condolence rally was held Wednesday for the teen who died after being set ablaze.Sonali Pal Chaudhury/NurPhot/REX/AP
Several hundred activists on Wednesday protested in Kolkata over the crime, notable for its shocking brutality even after a year in which several brutal sex crimes have been widely reported in India.
Activists also gathered in the capital New Delhi on Thursday, accusing the West Bengal government and police of failing to act swiftly after the girl lodged her initial complaint.
"We strongly believe that if your government had acted against the criminals ... the subsequent horrific events would have been prevented and the young woman's life could have been saved," the All India Democratic Women's Association, which organized the protest, and other activists wrote in a letter to the state's chief minister.
"The father of the girl ... had brought his family to Kolkata a few months back precisely because they had thought that the daughter would get a better education in Kolkata," the letter said.
A top state official said authorities would move quickly to ensure those responsible for the girl's rape and death were brought to justice, the Press Trust of India reported.
"All the accused against whom there are allegations have been arrested. We are committed to zero tolerance for sexual violence," West Bengal chief secretary Sanjay Mitra told reporters in Kolkata.
The rape, assault and harassment of women in India has been highlighted in the past 12 months after the fatal gang-rape of a 23-year-old student on a moving bus in New Delhi in December 2012 sparked nationwide outrage.
Parliament has since passed tougher laws to punish rapists.
Activists say rape victims often face severe threats and intimidation from their attackers, while police often discourage them from lodging complaints.