Five men appeared in court for the first time on Monday over the murder and gang rape of a 23-year-old student in New Delhi, amid chaotic scenes that forced the hearing behind closed doors.

A court source said that two of the men had offered to cooperate with prosecutors in exchange for more lenient sentences in a case that has sparked three weeks of protests and soul-searching about endemic sex crime in India.

The suspects, residents of New Delhi aged from 19 to 35, were brought to the court complex from the capital's high-security Tihar jail under high security due to fears for their safety.

"A charge sheet has been provided to the accused, and the next hearing will be on Thursday," magistrate Namrita Aggarwal told reporters after the brief hearing.

She earlier ordered the hearing to take place behind closed doors after journalists and lawyers packed the tiny courtroom which had chairs for about 30 people but was struggling to accommodate about 150.

Some lawyers staged noisy protests against the suspects being given defense counsels after two Supreme Court advocates stepped forward offering to defend the men in order to ensure a fair trial.

"It has become completely impossible for the courtroom proceedings to proceed," Aggarwal said in an order that forced all journalists and lawyers not connected with the case to vacate the stuffy courtroom.

The accused, who could face the death penalty if convicted, are charged with rape, murder and kidnap. A sixth accused, who is 17, is to be tried in a separate court for juveniles.

Though gang rapes are commonplace in India, the case has touched a nerve, leading to three weeks of sweeping introspection on India's attitudes to women, its often insensitive police force and justice system.

It often takes years to bring a case to court, but the fast-tracked legal proceedings are getting under way barely a week after the 23-year-old medical student died of her injuries in a Singapore hospital.

She had been out to watch a film with her boyfriend when they were lured onto a bus where the gang is accused of repeatedly raping and violating her with an iron bar, causing horrific internal damage.

The defendants have been named as Ram Singh, a bus driver, his brother Mukesh Singh, gym assistant Vijay Sharma, laborer Akshay Thakur and fruit-seller Pawan Gupta.

A court source, speaking on condition of anonymity, said that Thakur and Gupta had asked to become witnesses to the crime and cooperate with prosecutors.

Police have pledged "maximum security" during the hearing at the court amid fears for the defendants' safety. A man was arrested last week as he allegedly tried to plant a crude bomb near the home of one of the men.

Lawyers at the Saket court complex have decided to refuse to defend the accused, ignoring pleas from India's chief justice that the suspects be given a fair trial.

"No person should be hanged without a proper trial," said Supreme Court lawyer M.L. Sharma, who has offered to represent the men.

Legal experts say the magistrate Aggarwal will likely transfer the case to a higher court for trial.

Outlining their case before the same court in Saket on Saturday, prosecutors said there was DNA evidence to tie the defendants to the crime scene, as well as testimony from the boyfriend who witnessed the assault.

"The blood of the victim tallied with the stains found on the clothes of the accused," said Rajiv Mohan, part of the prosecution team.

Agence France-Presse