WikiLeaks founder Julian Assange joined about 800 people at a heavily-policed rally in London's financial heart on Saturday, part of worldwide protests against corporate greed and budget cutbacks.
The demonstrators, some of them masked, were pushed back by police as they marched from St Paul's Cathedral to the London Stock Exchange, situated around the corner from the famous landmark.
There were only minor scuffles with five people arrested, three for assaulting police officers and two for public order offences, Scotland Yard said.
"Today's protest has been largely calm and orderly," a statement said.
The demonstration went on after nightfall, with police urging protesters to leave the area.
Assange, flanked by bodyguards, got a warm reception from the demonstrators as he addressed them from the cathedral steps.
"One of the reasons why we support what is happening here in Occupy London is because the banking system in London is the recipient of corrupt money," the Australian said.
The marchers, bearing banners reading "Strike Back", "No Cuts" and "Goldman Sachs Is the Work of the Devil", were ringed by police cordons while mounted officers and vehicles stood by.
After London's police were severely criticised for being caught out by riots in August, they were clearly taking no chances Saturday and were out in force.
"Police have a duty not just to provide a proportionate response, but to minimise the potential disruption to Londoners going about their business. This isn't an easy balance to strike," said Scotland Yard.
"I'm here today mainly as a sense of solidarity with the movements that are going on around the world," he told AFP. "We're hoping for a kind of justice in the global financial system."
British student Amy Soyka, 22, who set up a tent outside the cathedral said: "I feel passionately that young people have been let down. All this hope and opportunity has been taken away from them... It's a terrible situation and we shouldn't even be in this economic situation."
But the protest, to the sound of guitars and drums, was overwhelmingly peaceful and the cathedral remained open to visitors.
Inspired by the Occupy Wall Street movement and Spain's "Indignants", people took to the streets across the world Saturday, targeting 951 cities in 82 countries.
Source: AFP European Edition