Demonstrations across the country reflect an enormous groundswell of anger against proposed increases to tuition fees, protesters said today.
Thousands of school pupils, students, lecturers and parents joined marches and occupied buildings in a bid to get their voices heard.
Students have accused Liberal Democrat MPs of planning to break their pledge to vote against raising fees.
Large numbers of protesters gathered in central London as further demonstrations took place in cities including Manchester, Liverpool, Sheffield and Bristol.
In London, Tom Lugg, 23, studying mental health nursing at Kingston University, Surrey, said: "It shows the young people of Britain are pretty angry.
"I don't agree with what some of them are doing but we have to empathise.
"Why should the next generation have to pay more? The Tories are hitting working families, just like they did with the Poll Tax."
Kate Thorogood, 18, studying adult nursing at Kingston University, said: "I think people are going about this the wrong way.
"I hope the message will get across because of the number of people here, but everyone is a bit wired and I don't agree with what they did to the van."
Former lecturer Derek Randall, 57, of Forest Hill, who has a daughter at university and two other children at secondary school, said: "I'm here with my son who's due to go to university next year.
"I wanted to be here because it's an attack on free education and I don't believe education is a privilege, it's a right.
"It will do nothing but widen the class divide.
"It's a much younger demonstration today, with pupils demonstrating against cutting the EMA (Education Maintenance Allowance).
"I don't know why they've kettled everyone in, they should just let everyone go slowly, especially when there are so many young people."
Freddie Winter, 19, from Wandsworth, south west London, studying at Lansdowne College, said: "I was at Millbank and it got overtaken by the violence.
"I don't think there'll be any of that today. Quite a lot of kids are here, school kids."
Griffin Dillyoung, 20, from Camden, north London, said: "I hope the message gets across this time.
"Everyone's quite hyped but I don't think it will turn violent.
"I wanted to be here because if someone can't afford to go to university, it's a complete waste of their talent, and that's not a good thing."
Several secondary school pupils wore their school uniforms as they marched in central London.
Melissa Relf, 18, from Essex, said: "We're not going to take this lying down, as the violence the other week showed. But it should be peaceful unless people hijack it."
A letter to Deputy Prime Minister Nick Clegg is expected to be delivered to Lib Dem HQ, which reads: "No amount of twisted reasoning from either you or Vince Cable can hide what everyone can see: you have lied to us.
"We call on you to withdraw Lib Dem support for Conservative cuts to our education system, or face the disappointment and anger of a generation that has been betrayed."
In Sheffield, Nina Fellows, 16, said up to 200 pupils had left her school - King Edward VII, in Broomhill, - to join the protest.
The Year 11 pupil said many had brought in notes from their parents to excuse them from lessons.
She said: "We're going to be going to university, hopefully, in the next couple of years and we're worried about our future."
Miss Fellows said many of the school students demonstrating were particularly angry about the future of the Education Maintenance Allowance - the small grant sixth formers receive which was scrapped in the Comprehensive Spending Review.
She added "It's a worrying time for us all. I've got my heart set on going to university."
Around 3,000 protesters in Manchester congregated outside the town hall.
The demonstration spilled onto Princess Street, causing traffic chaos in the city centre.
Police had directed the march to Castlefield, but a group broke away towards the town hall, and the rest followed later.
Around 30 officers blocked the entrance to the building as protesters sat down in front of them, chanting against education cuts and the coalition government.
Helicopters hovered overhead and officers surrounded the crowd, some on horseback.
Sarah Wakefield, of the University of Manchester Student Union, said: "We've had a really peaceful protest. We've worked very closely with police and I'm really pleased with the relationship with them and how it's gone.
"We finished the protest in Castlefield. Originally we were going to come to the town hall but we were concerned about numbers.
"Obviously some people decided they wanted to complete the march here, so very organically some people decided to move on to here."
In Cambridge more than 200 students scaled the fence of the Senate House, a building normally reserved for graduation ceremonies, and marched into the grounds of King's College shouting and waving placards.
Gabi Graczyk, a manager at Auntie's Tea Shop, located opposite the Senate House, said: "It's crazy out there. There are hundreds of students protesting and they look really angry.
"They're shouting and waving boards and chanting about fees.
"There's a huge police presence in the town and in the grounds of King's College.
"It came from nowhere. They're not being aggressive at the moment but who knows what could happen?"
Richard Johnson, a Cambridge graduate who works at the university's main library, said on Twitter that there were 12 police vans and cars present in the city centre.
Jamie Stern-Weiner, tweeting for political group New Left Project, said: "Police too strong and too many; had batons and were hitting students with fists."
He added that police were pushing students involved the protest.
A Cambridgeshire Police spokesman said: "The protests are concentrated in the Senate House at the moment, where the students have scaled the fence and that's where we are focusing our attention.
"Two arrests have been made for obstructing police and we're continuing to monitor the protest and see how it develops during the rest of the day."
Up to 3,000 people staged a noisy but peaceful protest march through Liverpool city centre.
Watched over by scores of Merseyside Police, the crowd brought traffic to a standstill and attracted workers out of shops and offices to wave and cheer in support.
Josh Wright, 22, president of the University of Liverpool's Guild of Students, said: "The great thing about these protests is that they are student-led peaceful protests.
"Peaceful protests are the best way of making the decision makers listen.
"We have to ensure that everyone who wants to go to university can go because of their academic ability, not their ability to pay."
In Bristol around 2,000 students came together from the city's University of Bristol and the University of the West of England.
The peaceful protest met with some clashes after officers tried to stop marchers heading further into the city centre.
Students had gathered at the University of Bristol's administrative building, Senate House on Tyndall Avenue, where a number made speeches.
They then marched from the University buildings down Park Street towards the centre of Bristol - halting traffic.
At the bottom of Park Street police formed a wall with officers on horseback.
Ryan Lech, 20, who is studying Drama at the University of Bristol, said: "We had a simple route down Park Street but we were sectioned off by a police wall, strengthened by these horse guards and vans, so people decided to sit down and as soon as we decided to sit down the police marched through us.
"The horses starting kicking us, nothing severe, but it was ridiculous, I've never seen anything like it.
"It was very unreasonable, no one did anything, no fireworks were lit, nothing happened until they formed the wall on Park Street, it makes no sense."
In Bristol, fireworks were let off by students, with one veering towards a police officer and spooking the horses which had been holding the students back.
Sussex Police said up to 3,000 students paraded through Brighton city centre as eggs and fireworks were thrown.
One Brighton University student, who gave her name only as Charlotte, 28, said: "I'm here today because I don't think it's necessary to increase fees.
"So much money has been spent on bailing out our banks and on Trident, people don't realise there are other ways of keeping the economy on an even keel.
"I'm really worried about education. Even though with increased fees, more money will be put in, less money will be spent on the actual teaching and the quality is going to suffer."
Protesters gathered outside Brighton University buildings in Grand Parade and chanted "shame on you" to those inside as 15 people went in.
Although education is devolved, Scottish students joined the protest against the cuts, with demonstrations in Glasgow and Edinburgh.
Tuition fees were scrapped in Scotland a decade ago and a graduate fee was abolished in 2008.
But there have been calls for graduates to make a contribution to their education once more as the sector attempts to scale back its spending.
In Glasgow, around 200 students at Glasgow School of Art entered the building for a peaceful demonstration.
Students also attempted to occupy Strathclyde University, campaign group Right To Work said.
There was a demonstration at Glasgow University, where a petition was handed to the secretary of the University Court.
Edinburgh saw around 300 students march from the city's Bristo Square to the Haymarket area this afternoon. Lothian and Borders Police said the event had been peaceful.
Students gathered for a rally in Glasgow's George Square.
Hundreds of students and school pupils marched in protest at the event, demanding that principals refuse to implement any cuts or job losses, and oppose the reintroduction of tuition fees in Scotland.
The action was called by the National Union Of Students and the Glasgow & Strathclyde University Anti Cuts Action Network.
West Midlands Police said around 40 students staged a "peaceful sit-in" at the University of Birmingham.
A spokeswoman for the university said protesters gathered at the entrance to the Aston Webb building.
She added: "Students and staff have a right to protest peacefully, however the safety of our campus community must be our main priority.
"Apart from a very small number of services in the immediate vicinity of the protest, our campus will continue to operate as usual.
"The university continues to work closely with our Guild of Students during what is a challenging time for all in higher education."
A crowd of around 300 students holding placards gathered in Glasgow city centre.
Part of George Street was shut to traffic as protesters chanted outside Strathclyde University's Royal College Building.
Among them were school pupils who walked out of class at lunchtime to join the demonstration, which appeared to be passing peacefully.
There was a strong police presence, with dozens of officers on the street.
A 16-year-old pupil from Dennistoun, who did not want to be named, said: "I don't know where I'll get the money to pay for my education.
"I was thinking of going to art school but that's probably out the window now."
Chris Murray, 18, from Motherwell, plans to study Social Sciences at the University of the West of Scotland next year.
He said: "It's unfair - the Tories are taxing people who weren't even able to vote in the last election. It's disgusting."
Student Liam Turbett said around 350 students had joined in a peaceful protest at Glasgow University.
He said the university students had been joined by pupils from Hyndland Secondary school in the west end of Glasgow.
He said: "It was the biggest demonstration we have had for years. We hope it will have a big impact".
A Strathclyde University spokesman said 30 students were occupying the university's Royal College building, with several hundred more gathered outside.
The spokesman said: "Police are attending. It appears to be peaceful and we are monitoring the situation."
Merseyside Police said an 18-year-old man was arrested after eggs were thrown during protests.
Assistant Chief Constable Andy Ward said: "I would like to thank all of those involved, residents, businesses and members of the public for their patience and co-operation throughout today.
"An appropriate policing plan, developed with our partners, was used to ensure minimal disruption in the city centre and the protests have passed without any incident.
"It is important that people have the opportunity to protest peacefully and my officers have worked hard today to facilitate everyone being able to express their views in a safe environment."
A series of sit-down protests took place in Lime Street, Castle Street, Church Street, Hanover Street, Hardman Street and Hope Place.