Thousands of anti-Wall Street protesters rallied in New York's Times Square on Saturday, buoyed by a global day of demonstrations in support of their monthlong campaign against corporate greed.

Inspired by the Occupy Wall Street movement, protests on Saturday started in Asia and rippled through Europe back to the United States and Canada. Protesters fed up with economic inequality took to the streets in cities from Washington, Boston and Chicago to Los Angeles, Miami and Toronto.

After weeks of intense media coverage, the size of the US protests on Saturday have been smaller than G20 meetings or political conventions yielded in recent years. Such events often draw tens of thousands of demonstrators.

In New York, where the movement began when protesters set up camp in a Lower Manhattan park on September 17, organisers said the protest grew to at least 5,000 people as they marched to Times Square from their makeshift outdoor headquarters.

'These protests are already making a difference,' said Jordan Smith, 25, a former substance abuse counselor from San Francisco, who joined the New York protest. 'The dialogue is now happening all over the world.'

The protesters chanted, 'We got sold out, banks got bailed out' and 'All day, all week, occupy Wall Street.' They arrived in Times Square at a time when the area is already crowded with tourists and Broadway theatergoers.

'This is disgusting' said Anatoly Lapushner, who was shopping with his family at Toys R Us in Times Square. 'Why aren't they marching on Washington and the politicians? Instead they go after the economic lifeblood of the city.'

American protesters are angry that US banks are enjoying booming profits after getting bailouts in 2008, while many people are struggling in a difficult economy with more than 9 percent unemployment and little help from Washington.

Some were disappointed the New York crowd was not larger.

'People don't want to get involved. They'd rather watch on TV,' said Troy Simmons, 47, who joined demonstrators as he left work. 'The protesters could have done better today ... people from the whole region should be here and it didn't happen.'

The Times Square mood was akin to New Year's Eve, when the famed 'ball drop' occurs. In a festive mood, protesters were joined by throngs of tourists snapping pictures, together counting back from 10 and shouting, 'Happy New Year.'

Police said three people were arrested in Times Square after pushing down police barriers and five men were arrested earlier for wearing masks. Police also arrested 24 people at a Citibank branch in Manhattan, mostly for trespassing.

Citibank was not immediately available for comment.

At about 8 pm, police arrested 42 people for blocking the sidewalk. Protesters complained they had no place to go with a wall of police in riot gear in front of them and thousands of demonstrators behind them leaving Times Square.

Five thousand people marched through the streets of Los Angeles and gathered peacefully outside City Hall.

The Occupy Wall Street movement has been gathering steam over the past month, culminating with Saturday's action. The protests worldwide were mostly peaceful apart from Rome, where the demonstration sparked riots.

But it was unclear if the movement, which has been driven using social media, would sustain momentum beyond Saturday. Critics have accused the group of not having clear goals.

In Toronto, a couple of thousand people gathered peacefully and started to set up a camp in one of the city's parks. Protesters in Washington marched through the streets.

'I am going to start my life as an adult in debt and that's not fair,' student Nathaniel Brown told Reuters Television. 'Millions of teenagers across the country are going to start their futures in debt, while all of these corporations are getting money fed all the time and none of us can get any.' - Reuters