The annual Million Mask March organised by secretive hacking group Anonymous led to violent clashes between protesters and police last night.
Central London saw chaotic scenes as scuffles broke out at the end of the march near to Trafalgar Square.
The protest was due to finish at 9pm but police say many activists refused to leave.
As police moved in to make a number of arrests, protesters started throwing bottles towards the police.
Others charged towards officers with some shouting ‘F**k the police’ during the violence scenes.
A protester holds a flare during the Million Mask March Police say problems started after they attempted to move protesters on following the march The Met Police say they made 53 arrests
Fireworks and flares were also let off.
Wearing trademark Guy Fawkes masks, supporters of the mysterious hacking collective Anonymous descended on areas including Trafalgar Square, Buckingham Palace and the Houses of Parliament.
Several glass bottles were thrown as police escorted one protester away as pockets of aggression moved sporadically around Trafalgar Square.
Scores of police officers maintained a tight perimeter around the masses.
Protesters wearing masks hold flares during protests near the Houses of Parliament, London, during the march Police form a wall outside Admiralty Arch Thousands of protesters hit the streets around major monuments in central London A protester screams from a statue in Whitehall Police hit the streets outside Big Ben at Westminster Protesters meet police officers during the march Protesters wave an anti US flag during the demonstrations Protesters demonstrate near the Houses of Parliament, London, during the Million Mask March
The protest is one of many similar marches held worldwide on November 5. Its agenda is broadly anti-capitalism and pro-civil liberties.
Ugly scenes marred last year’s march, with missiles and fireworks thrown at police, leaving four officers injured.
The Metropolitan Police imposed restrictions on this year’s event amid concerns over any repeat of the disorder.
A protester is watched by police near the march near the Houses of Parliament Protesters outside Buckingham Palace during the Million Mask March Crowds outside Buckingham Palace in London A protester stands in front of a car during the protest Protesters demonstrate during the Million Mask March while watched by police Protesters demonstrate near Big Ben Police said there were 10 arrests by 7pm tonight Protesters demonstrate near the Houses of Parliament, London, during the Million Mask March Masked protesters demonstrate near the Houses of Parliament, London, during the Million Mask March Protestors follow police down Whitehall, London, during the Million Mask March Many of the attendees held signs during the Million Mask March A protester with a placard outside the Houses of Parliament
Police imposed conditions on the march, limiting it to a three-hour period between 6pm and 9pm on a prescribed route between Trafalgar Square and Whitehall.
Any static protest must only take place in Trafalgar Square, Richmond Terrace and Parliament Square, and the Met has warned that anyone breaching the conditions could be arrested for public order offences.
Tried to get them all to make a peace sigh ✌️️they were a little shy #millionmask #annonymous pic.twitter.com/30sh1SNoO5
— ♪ads graham ♪( ´▽｀) (@adsgraham) November 5, 2016
Nearly 20,000 people had indicated they would attend on the event’s Facebook page, which warned "the police are not your friends".
The protest began peacefully, with several participants climbing the base of Nelson’s column and chanting the slogan "one solution, revolution".
One woman on a loudspeaker warned "there may be kettling" as the procession along Whitehall began.
Protestors demonstrate in Trafalgar Square during the Bonfire Night protest organised by Anonymous A protester lets off a flare near the Houses of Parliament, London, during the Million Mask March Masked protesters hold placards and wave flags as they stand on and around Nelson’s Column during the Million Mask March A masked protester holds a sign which reads ‘We Are Legion’ in Trafalgar Square Two arrests were for people refusing to remove their masks
The protest in Parliament Square dwindled by several hundred people at around 7.30pm as one man was seen being led away by officers.
Splinter groups roamed the length of the route between Trafalgar Square and Whitehall.
One man climbed atop the memorial to Field Marshal Haig and shouted "this is for all of us" to onlookers and passing motorists.
There were angry scenes as the procession continued, with police forming a ring of steel outside Parliament.
Officers stood firm, telling the protesters to stay within the boundaries.
Several supporters, masked and otherwise, argued they should be free to pass on public roads.
While most opted for a Guy Fawkes mask, the crowd was also dotted with people dressed in Darth Vader helmets, while others were wrapped in scarves.
One participant even brought a canine protester to join her as she blared NWA’s anti-authority anthem F*** Tha Police into the procession.
A protester demonstrates in Trafalgar Square Hundreds of anti-capitalists and anarchist took part in the annual Million Masks March Protesters and police assemble in Trafalgar Square
Plumes of smoke wafted into the cold night air as the protesters moved past Big Ben, with police marching behind.
Angela Windsor, an unemployed 40-year-old, said she travelled from Wales to take part in the event.
She said: "Nobody is protecting people – nobody cares.
The protest is one of many similar marches held worldwide on November 5 Police had a strong presence near the Houses of Parliament Protesters demonstrate near the Houses of Parliament, London, during the Million Mask March
"I think everyone here cares enough about people to make the effort to come down and try and do something, because the officials aren’t doing it."
She said anyone who tried to incite a repeat last year’s violent displays would be missing the point.
"Nobody wants a fight, we just want change," she said.
But she was forced to defend the wording of a sign she was brandishing – including the words "death to the monarchy" – when questioned about it by passers-by.
Later, some participants paused to read a message projected in green letters onto a building lining Parliament Square.
Masked protesters hold placards and flares as they stand on Nelson’s Column during the Million Mask March The protester’s agenda is broadly anti-capitalism and pro-civil liberty Protesters and police assemble in Trafalgar Square Police on horses in Trafalgar Square
It read: "Please observe Public Order Act restrictions. Failure to comply may result in arrest and prosecution. Officers may require you to remove facial covering. Failure to comply is an offence."
It came after members of the crowd ignited fireworks and flares in front of Westminster Abbey.