Activists from Occupy London wreaked havoc in central London following a day of industrial action that affected much of the UK.
Protesters, some wearing the Guy Fawkes masks, stormed Panton House in London’s Haymarket, leading to a police cordon of the area.
Earlier, some 200 activists from the anti-capitalist group assembled in Piccadilly Circus before moving into the building where the mining company Xstrata is based.
Around 40 protesters broke away from the main group and gained access to the building. They attempted to unfurl a large banner that read “power to the people”, however police quickly followed and removed the occupiers from Panton House.
Police then sealed off the area around Panton Street and marched through the 200-300 protesters, to shouts of "shame on you".
Reports suggest that four people have been arrested, though this remains unconfirmed.
A view of the London's Haymarket. Panton House is on the left.
The violence proved an exception to an overall peaceful day in which an estimated two million public sector workers took part in industrial action over a pension dispute.
Despite David Cameron calling the day of action a "damp squib", figures published by the Department of Education (DfE) show that three-quarters of schools in England (78%) were affected by the strike.
According to the DfE, 68% of schools in the UK were closed - 62% of schools in England and a staggering 99% in Scotland. In Wales, 86% of schools were were close, while half of all schools in Northern Ireland were shut.
The NHS also witnessed widespread disruption, with department of health figures showing that 54,000 appointments were cancelled along with nearly 7,000 routine operations.
The London Ambulance Service also came under “increased pressure”, with 30% more 999 calls today than normal, according to NHS London, with 42% of its staff taking part in the strike.
Speaking to the house of commons, the prime minister said:
"I want to thank all those people, including a number of people from 10 Downing Street, who are helping to keep our borders open and make sure Heathrow and Gatwick are working properly.
"So far the evidence would suggest that around 40% of schools are open and less than a third of the civil service is actually striking.
"On our borders the early signs are the contingency measures are minimising the impact. We have full cover in terms of ambulance services and only 18 out of 900 JobCentres have closed.
"Despite the disappointment of the party opposite, that support irresponsible and damaging strikes, it looks like something of a damp squib."
However, Union boss Bob Crow saluted those who took part in the action, and praised Metro workers on Tyneside for bringing the city of Newcastle to a halt.
Speaking to a crowd of workers on the Newcastle quayside, the RMT boss said:
"Brothers and sisters, I want to salute you.
"There is not a thing moving on the Metro today or on the Tyne.
"This Government wants to shift the balance of blame from the people that caused the austerity to the working man and woman.
"But it is the bankers and the bosses who have gambled with our country's future and you should not have to tolerate a worse pension and be forced to work longer to make up for their mistakes."