A day after violence in the city centre left scores of civilians and policemen injured, calm returned to the capital even as hundreds continued to protest demanding strict action against the rapists.

A Delhi Police constable badly beaten in the violence remained in critical condition.

Security forces Monday sealed off all roads leading to Rashtrapati Bhavan and India Gate, causing huge traffic jams, while Delhi Metro shut nine key stations to prevent demonstrators easy access to the capital's heart.

Shortly before meeting Russian President Vladimir Putin, Manmohan Singh said in a televised address that he shared the "justified anger and anguish" over the Dec 16 gang-rape but said violence was not called for.

"I assure you we will make all possible efforts to ensure security and safety of women in this country," he said, adding that he was a "father of three daughters".

"We will examine without delay not only the responses to this terrible crime but also all aspects concerning the safety of women and children and punishment to those who commit these monstrous crimes."

Home Minister Sushilkumar Shinde said the rapists won't be spared. "I will take action and I will not spare anyone," he told television channels.

At the Safdarjung Hospital, the 23-year-old rape victim's condition deteriorated due to internal bleeding.

"Her condition is bad and serious compared to yesterday," P.K. Verma, ICU in-charge, said.

"She continues to be critical but her kidneys are making urine and lungs are fine. She is conscious and communicating," he said.

The woman's plight has attracted nationwide sympathy and ignited mass anger, with thousands taking to the streets in Delhi and other cities and towns.

Under intense criticism, authorities Monday suspended two assistant commissioners in Delhi Police for not stopping the bus with tinted windows in which the rape took place for some 40 minutes.

Delhi's Lt. Governor Tejendra Khanna identified them as Mohan Singh Dabas of Delhi Traffic Police and Yad Ram of Police Control Room (PCR).

Deputy commissioners Prem Nath of Delhi Traffic Police and Satyavir Singh Katara of PCR were told to explain the police lapses. Three policemen had been suspended earlier.

The six accused, who have been arrested, were apparently drunk and on a joy ride. They had earlier robbed a man of Rs.7,000. But when he contacted police, they apparently failed to act.

With India Gate sealed off, hundreds -- the number swelling in the afternoon and again slipping towards evening -- massed near Jantar Mantar monument, about a kilometre from parliament.

Shouting "We Want Justice", the young and the middle-aged, watched by policemen and paramilitary personnel, waved placards and the Indian flags. Most people were huddled in small groups. Many were school students.

Protesters who spoke to IANS said that they were not convinced by the prime minister's assurance that the government would provide security and safety to women.

"It is just lip service and it won't work any more. We want action," said Abhijit Sinha, a Delhi University student.

Added Kanika, a medical student from Rohtak in Haryana: "We want justice and safety of women. The government should make strict laws that acts as a deterrent."

Many were angry that Delhi Metro's key stations had been shut.

"We will continue with our protests till concrete steps are taken," said Kavitha Krishnan of the All India Progressive Women's Association, one of several groups and NGOs taking part in the show of strength.