NEW DELHI: The fatal gang-rape of a student on a bus in New Delhi shattered India's silence over sexual violence and emboldened victims to speak out, family members and campaigners said Monday on the anniversary of the attack.

The victim's father, who cannot be named for legal reasons, said the assault on his 23-year-old daughter on a moving bus on December 16 last year “shook not just us but the entire country and the world”.

“We will only say that this date should be celebrated... so that people keep getting inspired and keep joining this movement, coming together to ensure the safety of women,” the father told India's NDTV network.

Her mother said her daughter's bravery before her death should continue to motivate Indian women to “fight and raise their voices against such crimes”.

The physiotherapy student suffered a savage sexual assault at the hands of six men, including with an iron rod, after she boarded a private bus while going home from the cinema with a male friend.

She died from her injuries 13 days later.

The brutality of the attack, and her determination to survive so she could report her attackers to police, sparked large-scale and sometimes violent protests as well as soul-searching about India's treatment of women.

The case led to reform of rape and sexual assault laws and shone an international spotlight on what Indian women's groups called a “rape epidemic” in the country.

Four of her attackers were convicted and given the death penalty in September after the case was fast-tracked, while a juvenile was sentenced to a detention centre.

While police expect annual figures to show a rise in the number of reported rapes, campaigners say the increase is in fact a welcome indicator of changing attitudes.

“Last year's movement seems to have empowered more people to speak out against sexual violence,” Kavita Krishnan, secretary of the All India Progressive Women's Association, told the Indian Express newspaper.

Divya Iyer, a researcher for Amnesty International, agreed that more women were coming forward to report attacks — but said it was a trend largely confined to towns and cities.

“Women have been empowered to speak out since the case and there are more crimes being reported. But you have to look at who are these women, where is this happening?” Iyer told AFP.

“It is mainly middle-class women. It is not across the board.... in rural areas in particular, access to justice is a problem.

“Not only is there social stigma, but there is no guarantee that their complaint of rape will be taken seriously by police, let alone result in a conviction,” she added.

Women, students and rights activists are expected to gather in the capital later Monday to hold a peaceful protest to mark the crime.

The victim's father said although penalties for offenders had increased and handling of assault complaints had improved, problems still existed, including the time taken to settle cases in India's notoriously slow legal system.

“It is true what happened to my daughter has caused massive changes in the system, but we still feel that it hasn't yet shown its complete impact,” he said.

“I really pray to God that something like this never happens again and no one has to go through something like this.”

Her mother said she would continue to fight for a tougher penalty for the convicted juvenile, who is serving a maximum three years in detention.

“We still hear her voice, her laugh and talk...we dream of her,” she said.