Two days after a 23-year-old paramedical student was gang-raped and brutally assaulted in a moving bus, Delhi Police on Tuesday claimed to have solved the case with the arrest of four people and said it will seek a fast-track trial for speedy punishment.

The condition of the victim continued to be critical but “better than yesterday’s”, doctors said on Tuesday.

Delhi Police Commissioner Neeraj Kumar told a press conference that the driver of the chartered bus, which was not legally permitted to run on normal routes, his brother and two more people have been arrested, while a massive manhunt has been launched to nab the remaining two accused.

Ram Singh, the driver of the bus, 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.

“Ram Singh 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.

But she was raped by Singh and other occupants of the vehicle which was being driven by Mukesh at the time of the incident.

The duo were then brutally assaulted and dumped near Mahipalpur flyover, he said.

Kumar said Delhi Police will seek a fast-track trial for this case on a day-to-day basis so that the accused are punished as soon as possible.

To a question, he said the maximum punishment for this crime was life sentence, but as far as the demands for death sentence for such crimes are concerned the Delhi Police will send a proposal in this regard to Government.

The Police is also likely to slap attempt to murder charge against the accused.

Kumar said the bus, which is primarily a school bus was being used for commercial purposes illegally by the driver.

Kumar said the girl was in a “serious condition” but that that there was some improvement. Speaking in the same vain, Dr B D Athani, Medical Superintendent of Safdarjung Hospital, said on Tuesday “Her condition is better than yesterday. Her conscious level is much better than yesterday’s. She underwent a surgery on Sunday.”

He told that the victim will be kept under “close observation” by doctors for the next 48 to 72 hours as the nature of injuries inflicted on her are as such.

Delhi ‘s Jawaharlal Nehru University students staged a demonstration outside Vasant Kunj Police Station.

Students, who were protesting outside the police station, said Delhi cannot stand women stepping out of their homes at night.

“We try to create awareness in every locality but nobody cares. Government and police must ensure that harassment of women in Delhi should stop. Only CCTVs won’t work,” one of the protesters said.