Police believe that crowds of students protesting about tuition fees last week were infiltrated by "organised groups of hardcore activists and street gangs bent on violence", Home Secretary Theresa May said today.
Mrs May said that police had already received a good public response to the publication of photos of suspected ringleaders and she expected significant numbers of arrests.
Some 35 people were arrested on Thursday as the demonstration against the tripling in university tuition fees descended into scenes of violence across central London, including an attack on a car containing the Prince of Wales and Duchess of Cornwall.
Following speculation that Camilla was struck by a stick pushed through the window of the royal couple's car, Mrs May confirmed that "there was some contact made".
Earlier Charlie Gilmour, the son of Pink Floyd frontman David, was released on bail after being arrested by Scotland Yard on suspicion of violent disorder and attempted criminal damage of the Union flag on the Cenotaph during the protests.
The Home Secretary called on student leaders unequivocally to condemn the "appalling" scenes of violence, and told the House of Commons: "This Government is determined to protect the right to peaceful protest, but violence is unacceptable and the perpetrators of that violence must be brought to justice."
While some students had behaved "disgracefully", it was clear that many of those committing acts of violence were "organised thugs", she told MPs.
Shadow home secretary Ed Balls also condemned the violence seen on Thursday, but also stressed that Labour MPs "share the dismay and anger and injustice felt by hundreds of thousands of students and young people at the deeply unfair hike in tuition fees and the abolition of Education Maintenance Allowances".
Mr Balls urged Mrs May to shelve a cost-cutting review of royal security which he said was on her desk, at a time of increasing threats and in the run-up to the wedding of Prince William and Kate Middleton next spring.
And he called for her to commission a wider review of the current level of threat and the arrangements for the security of the Royal Family.
More than 30 police officers were injured last Thursday as protesters hurled bottles, stones, paint, golf balls, snooker balls and flares and used metal crush barriers as weapons, said Mrs May.
Six officers required hospital treatment, all of whom have been released. Meanwhile, an Independent Police Complaints Commission inquiry has been launched into the injuries sustained by a protester who required surgery to his brain.
Referring to the violence committed by protesters, Mrs May told MPs: "It is quite clear that these acts were not perpetrated by a small minority but by a significant number of trouble makers.
"Some students behaved disgracefully but the police also assess that the protesters were infiltrated by organised gangs of hardcore activists and street gangs bent on violence.
"Evidence from the other recent protests shows that many of those committing violence were organised thugs as well as students. It is highly likely that this was also the case last week.
"I want to be absolutely clear - the blame for the violence lies squarely and solely with those that carried it out. The idea that police tactics ... were to blame when people came armed with sticks, flares, fireworks, stones and snooker balls is as ridiculous as it is unfair."
With more student protests expected when the House of Lords debate tuition fees tomorrow, the president of the Association of Chief Police Officers said that the use of water cannon was inappropriate to deal with demonstrations of the kind seen last week.
"They are a blunt instrument," Sir Hugh Orde told the BBC Radio 4 Today programme.
"The tactics used over the last week have been that small groups of very violent people have embedded themselves in large groups of very peaceful people and to try to use water cannon in that situation would be very difficult and would upset an awful lot of people."
But an Acpo spokesman made clear that the use of water cannon had not been ruled out for the future.
The spokesman said: "The Acpo manual on public order includes a full range of tactical options including water cannons and others more common to UK public order events, such as cordons and mounted police.
"All are open to public order commanders against principles of proportionality and necessary use of force. The key is employing the tactic appropriate to each situation. That is for ground commanders to judge."
Gilmour, 21, was arrested at his family home in Sussex yesterday by officers from the Metropolitan Police and was taken to a Sussex police station where he was also questioned on suspicion of theft.
The Cambridge University student issued a public apology after being identified as one of those who climbed on the Cenotaph, the nation's monument to its war dead, as thousands of youngsters vented their fury over the decision by MPs to treble university fees to a maximum of £9,000 a year.
A Metropolitan Police spokesman said Gilmour was bailed until a date in June pending further inquiries.
Mrs May confirmed that a Metropolitan Police review of royal protection in the wake of the assault on Prince Charles' car would report by December 17.
But she said it was likely that only limited detail from the report would be made public.
The head of Scotland Yard's public order branch, Commander Bob Broadhurst, tonight raised the possibility of the Met using water cannon.
In a statement he said: "There has been a great deal of speculation over the weekend about the Met using water cannons. There are no current plans to use water cannons on the streets of the capital but we would be foolish if we did not take time to look at tactics such as this to see if it might be appropriate in the future.
"I would emphasise we will not rush in to anything and we are not in the business of knee jerk reactions.
"Anything we do will be carefully and fully considered to ensure the best outcome for protesters, officers and all Londoners."
With more student protests expected when the House of Lords debates tuition fees tomorrow, Mr Broadhurst said: "We will take whatever steps are necessary to protect life and property.
"As I've said before, a significant violent element has hijacked the previous demonstrations from genuine peaceful protesters.
"We have also seen some people get carried away in the heat of the moment and get involved in violence which they would never normally consider.
"My message to these people is clear and unequivocal - make no mistake, if you indulge in reckless violence, injuring officers and innocent people, we will track you down and you will face the consequences. Those consequences could change the path of your life forever.
"By all means exercise your democratic right and protest, but this has to be peaceful otherwise you cross the line from protester to criminal, and this has the potential to affect your future opportunities in life."
Scotland Yard said section 60 stop and search powers would be used in Westminster "to prevent troublemakers hijacking peaceful protests".Reuse content