New York police have dismantled the Occupy Wall Street camp in Zuccotti Park and arrested about 200 people following a raid in the early hours.
Protesters were ordered to leave at about 01:00 (06:00 GMT), before police began removing tents and property.
The New York camp was set up in September to protest against economic inequality - it inspired similar demonstrations around the world.
It was the latest camp to be cleared by police in US cities in recent days.
Following Tuesday's eviction, a New York state judge issued an order ruling protesters could return to the park, pending a hearing at 11:30 (16:30 GMT).
But the city's Mayor Michael Bloomberg said the park would remain closed while officials reviewed the legal situation.
In a news conference, Mr Bloomberg said there was a conflict between protecting public health and safety and protesters' First Amendment rights.
"Unfortunately, the park was becoming a place where people came not to protest, but rather to break laws, and in some cases, to harm others," Mr Bloomberg said.
"The First Amendment gives every New Yorker the right to speak out - but it does not give anyone the right to sleep in a park or otherwise take it over to the exclusion of others."
Police in New York gave an announcement as their operation began, telling protesters: "The city has determined that the continued occupation of Zuccotti Park poses an increasing health and fire safety hazard."
Leaflets were handed out telling occupants to "immediately remove all private property" and warning they would be arrested if they interfered with the operation.
Any belongings left behind would be put into storage, said the notice, and demonstrators would not be allowed to bring camping equipment back.
Street cleaning crews then moved in to clear rubbish and hose down the privately owned park.
The area around the park was sealed off and journalists were prevented from entering. Some of the activists accused police of using excessive force and pepper spray.
Police spokesman Paul Browne said most people left the park when ordered, but that a small group of people had refused.
The 200 or so people arrested included some who had chained themselves together.
The authorities say the park has been cleared for cleaning, and that protesters would be allowed back into the park, but without the encampment.
Hundreds of people moved to nearby Foley Square to continue their demonstration. A message was sent from a Twitter account, @OccupyFoleySq, set up on Tuesday morning, saying: "We are here and growing."
The city authorities and Mayor Bloomberg had come under pressure from residents and businesses to shut down the camp, which had about 200 occupants as it neared its two-month anniversary.
There had been plans for a street carnival to descend on Wall Street on Thursday in an attempt to shut it down, to mark the camp's two-month anniversary.
By daylight the camp had been entirely cleared, a step welcomed by some local businesses.
"I support them but we have to work, not do revolution," a juice stall vendor told the AFP news agency. "I don't support revolution or idleness. Idleness is not good for our country."
But activists released a statement saying that while they may have been physically removed, "you can't evict an idea whose time has come".
The Occupy movement, inspired by the Arab Spring uprisings and economic protest camps in Spain, is calling for a more equal distribution of the world's wealth and a fairer response to the global economic crisis.
The most high profile protest has been Occupy Wall Street in New York, which began on 17 September. The protesters call themselves "the 99%" and are demanding major reforms of the global financial system by curbing the power of banks and corporations. Protests have also taken place in cities across the US, including Washington DC, Chicago, Los Angeles, San Francisco, Denver, Pittsburgh, Detroit, Houston and Boston. On 15 November, police moved in to clear the Occupy Wall Street protest, earlier they had cleared camps in Portland, Oregon and Oakland, California.
A protest in Madrid's Sol Square began in May and turned into a week-long sit in. Renewed protests in Europe started on 15 October with demonstrations in Rome, Berlin, Frankfurt, Leipzig, Hamburg, Dublin, Bucharest, Zurich and other cities. Demonstrations were largely peaceful, but around 70 people were injured when violence broke out in Rome.
Protests at the London Stock Exchange in solidarity with Occupy Wall Street began on 15 October. After being denied access to Paternoster Square in front of the stock exchange, demonstrators organised a camp of around 150 tents outside St Paul's Cathedral. Protesters were told their camp could remain until the new year, on condition some tents blocking the "public highway" were removed. But the City of London Corporation said it was proceeding with legal action on 16 November, after talks with the protesters broke down.
Demonstrations and protest camps began on 15 October in major cities, including Calgary, Halifax, Quebec, Toronto, Vancouver and Victoria. Police have cleared protesters from sites in Halifax and Ontario but campaigners at the biggest camp, in Toronto, have been allowed to remain.
Protests began in Sydney and Melbourne on 15 October. Police forcibly removed around 100 demonstrators from the Melbourne camp on 21 October.
Organisers in the US say most of the country's money is held by the richest 1% of the population and that they represent the other 99%.
The New York clearout comes after police arrested 33 people in Oakland, California as they closed the protest camp in Frank Ogawa Plaza early on Monday morning.
There was a fatal shooting near the camp last week and Oakland Mayor Jean Quan said she had to evict the demonstrators "before someone else got hurt".
In similar clampdowns in recent days across the US:
- Police in riot gear arrested 50 people as they cleared a protest camp in Portland, Oregon on Sunday evening
- Police in Burlington, Vermont, evicted demonstrators on Sunday days after a military veteran shot himself dead inside a tent at their camp
- Encampments in the cities of Denver, Colorado, and Salt Lake City, Utah, were cleared on Saturday
- Lawyers for Occupy St Louis in Missouri plan to take their bid to regain their downtown campsite to federal court on Tuesday after it was also cleared on Saturday
A number of other US cities have seen protests camps spring up in the past two months, and the Occupy movement has also spread to Europe, South America and Asia.