28 March 2011 Last updated at 02:45 ET
Police clashed with violent groups at several flashpoints in central London .Police have charged 149 people after unrest broke out alongside a peaceful anti-spending cuts protest in London.
A mob attacked police officers, smashed windows and daubed banks and shops with paint on Saturday, during and after a march and rally organised by the TUC.
A total of 201 arrests were made, most of them after a campaign group staged a sit-in at a luxury store on Piccadilly.
Scotland Yard said the violence from some people “could not have been more markedly different” to the TUC event.
Business Secretary Vince Cable said the government will not change its economic strategy as a result of the TUC protest.
The TUC said 250,000 to 500,000 people attended the march, which passed off without incident.
But a separate group wearing scarves to hide their faces started attacking shops and banks, clashing with some of the 4,500 police on duty.
The main organisation involved in the protest was the TUC.
It organised the rally which attracted more than 250,000 demonstrators. Its message was that the government’s spending cuts go too far. Other protests were staged by a variety of activists.
The UK Uncut group aims to highlight what it describes as the inequality of the British legal and tax system which it claims enables wealthy individuals and firms to pay a fraction of the tax of smaller. It aims to use direct action but does not advocate violence.
That cannot be said of a third group out in force – anarchists and anti-capitalists appear to have used the cover of the march, and the UK Uncut protest, to target what they see as symbols of capitalism.
Many retailers are privately livid that the image of ruined shop fronts might damage their businesses in the long run.
Trouble flared in central London in Oxford Street, Piccadilly and Trafalgar Square.
The Metropolitan Police said 145 of the arrests were in connection with a demonstration by campaign group UK Uncut, which occupied luxury grocery store Fortnum & Mason in Piccadilly in protest over alleged tax avoidance by the business’s part-owners.
On Sunday 138 of those were charged with aggravated trespass and were bailed to appear at Westminster Magistrates’ Court on various dates, beginning on 9 May. The remaining seven were bailed pending inquiries.
UK Uncut, which has carried out a number of protests in recent months, has distanced itself from protesters who damaged property and attacked police on Saturday.
The remaining people were charged for various offences, including possession of an offensive weapon, violent disorder, assault on police, criminal damage and drunk and disorderly behaviour.
Commander Bob Broadhurst, who led the Met Police operation, revealed activists had developed their tactics to avoid police by staying on the move, using alleyways and covering their faces.
“Their intent appeared to be causing havoc, with no concern at all for those people in central London they were putting in danger,” he said.
“Officers came under attack, fires were set and shops attacked. These are criminal acts and I cannot call them anything different.”
Mr Broadhurst has warned that anarchist groups may also be planning to target the wedding of Prince William and Kate Middleton, on 29 April.
The force has faced some criticism of the way it handled the protest, with former Met Deputy Assistant Commissioner Brian Paddick saying officers should have done more to protect property.
But London’s deputy mayor Kit Malthouse said officers had a “difficult balance” to strike between policing the main demonstration and unrelated incidents of violence including attacks by anarchist groups.
Scotland Yard said it was considering making greater use of stop and search powers to prevent troublemakers from behaving violently at future public events in London.
In a statement the Met Police said stop and search powers would still need to be used in an “intelligence-led” way.
“We must have the grounds to use the power. What we will look to do in the future is see if we can deploy officers at transport hubs and interchanges to identify, based on intelligence, those people who may be causing trouble.”
Order was restored in the early hours of Sunday after some people were contained by police for several hours in Trafalgar Square.
There were 84 reported injuries during the protests, including at least 31 police, with 11 officers requiring hospital treatment.