Occupy Wall Street activists clashed on Thursday with workers and police outside the New York Stock Exchange, prompting over 150 arrests on the two-month anniversary of the anti-capitalist movement.

As hundreds linked arms to block access to the NYSE building, several violent scuffles broke out with organizers vowing a show of force despite recent setbacks for the Occupy Wall Street campaign which has gone global.

Chanting 'Wall Street's closed!' 'We are the 99 percent' and 'Whose street? Our street!,' about 1,000 demonstrators engaged in a tense face-off with hundreds of police, including many on horseback outside the iconic exchange.

The protests were part of a 'Global Day of Action' with hundreds of demonstrations planned across the United States. Police evicted protesters in Los Angeles and Dallas on Thursday, arresting dozens of people.

PROTESTS ACROSS THE GLOBE

In London, protesters refused to budge as a deadline to leave their camp outside St Paul's Cathedral by 1800 GMT passed, with the City of London Corporation now expected to start legal action to remove them.

Thousands also marched in Spain and Athens to protest austerity measures and public spending cuts, although the demonstrations were not directly linked to the OWS movement.

'OVERWHELMING NUMBER'

After skirmishes throughout the morning in New York, up to 2,000 people regrouped in Zuccotti Park, the symbolic heart of the movement, where the Occupy camp was dismantled by police in a night-time raid early Tuesday. "We need to show we are bigger than Zuccotti Park, that we are resilient, that we refuse to submit to brutal police tactics," said Jessica Lingel, 28, a librarian from New Jersey.

The protesters were preparing for a later march joined by union members, planning to swarm the Brooklyn Bridge and disrupt evening commuter traffic.

"The numbers I've heard is something less than a thousand, but it's hard to tell because you have a group here and another group there and some go from one group to another," Mayor Michael Bloomberg told reporters.

"But it is not an overwhelming number," he added, saying "most people were able to go about their business."

177 ARRESTS

New York police commissioner Ray Kelly said seven police officers had been hurt in the morning clashes and 177 people had been arrested.

The level of participation in the rallies could provide a clear indication of Occupy Wall Street's clout exactly two months since the movement sprang up to denounce corporate greed and the world's wealthiest 'one percent'.

While the stock market opened on time at 9:30 am (1430 GMT), protesters managed a 45-minute blockade outside the NYSE. Police eventually intervened to break through, establishing a corridor to escort traders and workers.

Amid chaotic scenes, police then moved in to clear the street, and ensuing clashes sent police and protesters clattering to the ground. One man was repeatedly clubbed with a police baton, while several protesters were handcuffed and dragged into police trucks.

Several groups split up and moved in different directions, deploying to choke points around lower Manhattan, blocking the area until police could move in and clear it.

At least one exasperated New York cop seemed to concede victory to the protesters.

"They've blocked everything off. This is what happens when you kick them out of the park: you stir a hornet's nest," said the officer who would not provide his name. "They wanted to disrupt Wall Street, and they've done it."

In Washington, more than 200 protesters set off from the Occupy DC encampment, just meters from the White House, for the Francis Scott Key Bridge over the Potomac River, marching through the heart of the US capital.

The marchers set off down K Street, where some of the most influential lobbyists in Washington have their offices, chanting 'We are the 99 percent' alongside a police escort that included four Clydesdale horses.

SOME OPPOSING OCCUPY STIR?

According to activist group MoveOn, more than 460 protests were planned across the country Thursday.

But in a survey released Wednesday, Public Policy Polling said it appeared Americans were moving against the Occupy movement, with 45 percent of respondents opposing its goals versus 33 percent in favor.

"That now makes the movement less popular than its right-wing counterpart, the Tea Party," which enjoyed 42 percent support, the polling institute said.