NEW DELHI: An Indian court upheld Thursday the death penalty handed to four men convicted of the fatal gang-rape of a student in New Delhi, an attack that triggered protests over violence against women.

The High Court rejected an appeal by the four who were sentenced last year to hang following a trial over the attack on the 23-year-old student on a moving bus in the capital in December 2012.

A lawyer for the four said he would now appeal against the sentence to the country's top court.

“Our appeal has been dismissed by the high court. The death sentence of the four convicts has been upheld. We will go to the Supreme Court,” AP Singh told reporters outside the court.

“This is a politically motivated decision,” he added.

The physiotherapy student was attacked by 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 identify her attackers to police, sparked large-scale angry street 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 women's groups called a “rape epidemic” in the country.

Four of her attackers were convicted last September after the case was fast-tracked, while a juvenile was sentenced to three years in a detention centre. A sixth man was found dead in jail.

The woman's mother, who cannot be identified for legal reasons, welcomed the decision, saying the family was “inching closer to justice”.

“Complete justice will be delivered when all the convicts are hanged to death,” she said outside the court.

“The juvenile accused should also get the same punishment,” she said.

The High Court dismissed the men's appeal as well as confirming the death penalty handed down by the trial court after consideration.

As part of Indian legal procedure, the High Court is required to review the death penalty delivered by a lower court.