91Èȱ¬

The Metropolitan Police Commissioner has said "the game has changed" in policing protests and is expecting "more disorder on our streets".

Sir Paul Stephenson's comments come the day after the second mass student protest was held over tuition fees.

He was cross examined on Thursday by the Metropolitan Police Authority.

A police report found the numbers attending the march on 10 November were significantly under-estimated by police and the National Union of Students.

Student activists criticised the "heavy handed brutality" of London's police during Wednesday's protests.

The Education Activist Network (EAN), which helped organise that protest, also said a follow-up day of action is being planned for next Tuesday, billing it as a national student strike.

Sir Paul said that "the bottom line is we didn't get it right two weeks ago, and in my opinion we did get it right [on Wednesday]".

The Commissioner also admitted that the police made mistakes during the demonstrations earlier this month, which led to a riot at the Conservative Party's headquarters on Millbank in central London.

He added that, in the future "we are going to be much more cautious. We are into a different period I am afraid. We will be putting far more assets in place to ensure we can respond properly. Essentially the game has changed".

The controversial decision to contain demonstrators - so-called kettling - on Whitehall on the latest protest was reached, he said, because of intelligence that some protesters were intending to try to occupy the Liberal Democrats headquarters on nearby Cowley Street.

Sir Paul acknowledged that letting people out from the cordon last night was "frustratingly slow" but "water and toilets were requested and delivered".

He said: "It was a crime scene. We let out vulnerable people... we took off our helmets to calm people down."

Britain's most senior police officer also said that his force "will be making greater use of social networking sites" such as Twitter and Facebook prior to demonstrations in the future.

This is because many of those participating in both protests used Facebook and Twitter to organise themselves in advance.

Sir Paul said there were 35 arrests connected to Wednesday's protest in London. Nine of those were in connection with damage caused to a police van that was left in the middle of the demonstration.

Seven police officers were injured, with two requiring hospital treatment.

The student protests in London a fortnight ago saw protesters storming Conservative Party, throwing missiles at police and resulted in more than 40 officers being injured.

91Èȱ¬ home affairs correspondent, Danny Shaw said the report into that protest says Scotland Yard significantly under-estimated the number of demonstrators - about 25,000 people took part.

The review by Commander Simon Pountain says intelligence gathered beforehand suggested there would be no disorder and that the trouble that did occur involved students with no history of violence.

Our correspondent said the report's "key finding" was that the focus of the rioting - Tory HQ at Millbank - had not been identified by police as a vulnerable location.

It added that not enough police were deployed to protect the building and there were not enough officers in reserve.

A statement from the EAN was critical of the police's tactics in London.

It said: "In London the heavy handed brutality of the police force denied thousands the right to protest. Police saw fit to kettle students as young as 14 for hours on end in the cold. They were prevented from handing a letter to Nick Clegg.

"A Downing Street rally - for which Scotland Yard's permission had been sought and received by the Education Activist Network - was arbitrarily banned at the last minute by the police, who charged the waiting crowd on horseback."

The statement also said that Wednesday's protests "underlined what November 10 had already shown - there is mass, deep-seated and furious opposition to the government's education cuts.

"The sheer number of walkouts, protests and marches yesterday, from the smallest school to most of Britain's major cities were too numerous for the media to count."

The 91Èȱ¬'s Greg Wood said he saw horseback charges by the police "at the Trafalgar Square end of Whitehall".

Our correspondent added: "Glass bottles and cans of beer were thrown at the police and some arrests were made. Many within the crowd had their faces concealed, and they were pushing against the police line."

Arkady Rose, from London, is mother of 15-year-old Kathy, who was kettled in Wednesday's protests. She said she was proud of her daughter's participation in the protest.

She added: "After all, it's her life and education that's going to be affected by the changes.

"Kathy wasn't released until after 8pm and she says that there were still students younger than her in there, despite the police saying there weren't. She says she saw teenagers of her age being beaten with batons and people who were asking to leave for medical treatment being refused.

"It seems like the kettling started around the time that most students had had enough and were wanting to go home. The police seem to have kept them moving around by changing the story and moving them from exit to exit with the intention of tiring them out.

"There was no food or water, despite what they say. All my daughter managed to eat all day was a bag of Minstrels."