The health of the girl, a para-medical student who is battling for life in Safdurjung Hospital, deteriorated this evening and she was put on "full time ventilator support".
The arrests today came on top of detention of two men last night in connection with the incident that took place oat around 9:30 pm in a moving bus on Sunday in south Delhi.
Two days after the incident in which her male friend, an engineer, was also attacked for standing up to the rogues and both thrown out of the bus, both the Houses of Parliament had an impromptu discussion on the issue.
Members expressed anger and concern over safety of the women in Delhi with cinestar-turned-MP Jaya Bachchan even breaking down in the Rajya Sabha.
In both the Houses, members felt that the existing laws were not deterrent enough to prevent such crimes and they demanded law should be amended to provide for death penalty.
Home Minister Sushilkumar Shinde said he agreed with the views of the MPs and promised to take necessary steps to ensure safety of women in Delhi, including increased police patrolling.
"It is proposed to have this case tried by a fast-track court, with a request for day-to-day hearing, so that the trial does not linger...If there are any lapses, strict action will be taken against the police officers concerned," he said.
Delhi Chief Minister Sheila Dikshit urged Delhi High Chief Justice to immediately make functional five special fast track courts to try cases of assault on women as approved by her government.
NHRC observed that the incident raised the issue of declining public confidence in law and order machinery here while seeking the reports within two weeks.
Both the victims had suffered serious injuries in the assault and after they were thrown out of the bus in a semi-nude condition.
Investigators have already said that they will seek a fast-track trial for speedy punishment in the case as well as write to Union Home Ministry seeking laws for invoking death penalty for rapists.
Ram Singh, the driver who was today remanded to five day custody, his brother Mukesh, Vinay Sharma, an assistant gym instructor and Pawan Gupta, a fruit seller, were on a "joy ride" on Sunday night when they crossed Munirka bus stop where the paramedic student and her male friend were waiting for a bus to Dwarka, Delhi Police Commissioner Neeraj Kumar said.
Kumar said two men are still absconding in connection with the incident. However later in court, police said three persons were absconding and they need to send teams to Bihar, Uttar Pradesh and Rajasthan to nab them.
"Ram Singh, who was not driving the vehicle that night, shouted that the bus was going to Dwarka and asked the couple to get into it. Once the bus started moving, they started misbehaving with the girl. Her male friend who protested and tried to save the girl was severely beaten up. The girl also tried hard to protect him," Kumar said.