LONDON, England (AP) - About 500 people critical of the economic impact and corporate flavour of the London Olympics marched Saturday near the Olympic Park, determined to send a message that Britain is not united in backing the games.

The protest march came hours after police arrested more than 130 bicyclists who had defied an order to avoid cycling in groups around the stadium during Friday night's opening ceremony.

Police said they had ordered the protesters to remain south of the River Thames, to keep them from blocking thousands of ticket-holding guests from attending the opening ceremony. The cyclists said they were held in a cordon by police, and later arrested, for trying to cycle in lanes restricted for official Olympic traffic.

Occupy London, part of a global movement that has waged demonstrations against financial institutions and capitalist policies, said some cyclists were members of the movement. They said police cordoned off more than 100 cyclists at one road junction near the stadium as Friday's ceremony was beginning and held them there several hours.

Saturday's protest, the largest so far against the games, drew a mix of left-wing and green activists who decry the Olympics as a corporate juggernaut rolling over residents and their civil rights.

They marched peacefully, chanting against what they called the "Corpolympics," watched by police officers on foot and motorcycle.

The protesters contend that the often-cited Olympic boost to traditionally gritty, working-class east London is an illusion, whereas major corporate sponsors such as McDonald's and Coca-Cola gain from the 9.3 billion pound ($14 billion) games. They said the mass arrests at the cycling demonstration, and limits on corporate branding designed to protect sponsors, show that the games are a threat to civil liberties.

Underscoring that message, the marchers passed one of the apartment buildings that have had British army ground-to-air missiles deployed on its roof. That security measure, designed to stop a hijacked aircraft from being crashed into an Olympics venue, has drawn fierce local opposition.

Olympics organisers and the government say the games will leave a legacy of thousands of new homes and jobs, and a major new park in a long-deprived area.

One protester, Michael Coulston, said the British government chose to spend billions on attracting visitors "to one location for a couple of weeks" rather than to build infrastructure of lasting benefit to all Londoners.

Like many on the march, Coulston said he doesn't object to the games themselves, but feels that recession-hit Britain was sending out a false message: "Let's pretend to the world that we're happy."

Many Britons were initially unenthusiastic about the games, a pessimism bolstered by pre-Olympic headlines about security troubles and feared transit chaos. But the mood has lifted now that the event is happening, especially after director Danny Boyle's spectacular opening ceremony.

East End resident Leonard Grieves, who came out of his house to wave an Olympic flag at the passing protesters, said the games had brought real benefits to the district.

"We've seen the area go from almost a wreck to a really nice place," he said.