Black-clad anarchists and other hardcore demonstrators have caused havoc across central London, overshadowing the more peaceful mass march which ended earlier.
Numerous shops in Oxford Street, Soho and Piccadilly were targeted as police attempting to protect property found themselves bombarded with paint, coin-filled heavy duty fireworks and even ammonia-filled lightbulbs.
By late afternoon on the luxury retail shop Fortnum and Mason, which had been occupied by protesters.
Some demonstrators had climbed on the roof of the shop on Piccadilly and for a lengthy period a thin line of police officers struggled to prevent more protesters entering the shop.
Eventually the UK Uncut group ended its sit-in after several hours, prompting police to move in and make arrests on the grounds of aggravated trespass.
Other shops nearby, including a branch of Santander, a branch of Lloyds and a Starbucks, also suffered damage.
Earlier police lines were deployed to protect some damaged shop fronts, including Topshop's flagship branch on Oxford Street which was one of the first to have its windows smashed. The Ritz Hotel also suffered damage.
The major Oxford Circus junction was blocked by demonstrators, who burned a large Trojan Horse in the middle of the road.
Police began seeking to push protesters back shortly after 18:00 GMT, as a violent and chaotic day in the capital drew to a close.
But more heavy-duty fireworks saw officers forced to remove their flammable fluorescent outer layer.
The Met said one police officer had been hospitalised by injuries, while a further three had also suffered injuries.
By 16:40 GMT 13 people had been arrested for criminal damage and public order offences.
The Metropolitan police's public order branch stated on its Twitter feed: "Be aware that police have had light bulbs filled with ammonia thrown at them in the Oxford Street area."
For much of the afternoon the police struggled to contain the fast-moving, fluid Black Bloc anarchists as they spread across the capital's wealthy West End.
"Protesters splitting off in all directions around Soho, not staying anywhere long enough to be contained," politics.co.uk's editor Ian Dunt tweeted from the scene earlier this afternoon.