A group of more than 1,000 students has marched across central London in a protest that has seen a police van attacked.
BBC correspondent Tom Symonds said a group had got through closed gates into an area alongside the University of London Senate building in Bloomsbury.
The students moved through Trafalgar Square, Piccadilly and Hyde Park Corner after blocking streets in Holborn.
Metropolitan Police officers have monitored the group but not moved in.
One police van was attacked with protesters hitting the vehicle's windscreen and opening its doors while officers inside tried to close them.
Both Senate House and the adjacent Stewart House were briefly closed.
Chris Cobb, chief operating officer and university secretary, said: "There have been a few instances this afternoon of aggressive behaviour, which marred a largely peaceful demonstration.
"I appreciate that the vast majority of protesters acted in an orderly way, but it was shame that a few were intent on causing trouble."
The students are protesting about the way the police handled last week's protest, which was over the future of the students' union and cleaners' contracts.
Forty-one people were arrested following two days of demonstrations.
Protesters have claimed the police were "heavy-handed"; however, the Met said it had not received any complaints about the actions of its officers at the protests.
The University of London was granted an injunction preventing "violent and intimidating" protests on its campuses.
Our correspondent said the protest was now falling in numbers, with students flanked by numerous police vans.
National Campaign Against Fees and Cuts spokeswoman Hannah Webb said the demonstration had started peacefully enough as police stayed away to try "not to upset people", but their increased presence throughout the afternoon had created tension.
She said the demonstration had split into two main groups, with one congregating around Parliament Square.
The protest is part of a planned "day of action".
The Met said: "We will always look to facilitate peaceful protest.
"What we must balance is the rights of people to protest with the public's right to go about their daily business.
"We have had an appropriate policing operation in place throughout the course of this afternoon, including pre-deploying officers at a number of central London locations."
- 7 December 2013
- 5 December 2013