New York City, still recovering from the devastation of Usama bin Laden's attack on the World Trade Center, braces this week for another assault — this time by leftist protestors and anarchists bent upon disrupting the World Economic Forum. 

The city's police, widely regarded as heroes following Sept. 11, will be working 12-hour shifts guarding the Waldorf-Astoria Hotel on Park Avenue, where the world's business and political leaders will be meeting from Thursday through the weekend until Monday. 

Officers in full riot gear have spent the past few weeks rehearsing crowd control at Shea Stadium, and top police officials have consulted with their counterparts in Seattle, Genoa and Quebec City, scenes of previous anti-globalization violence. 

Demonstrator leaders say, as always, that they oppose violence and want simply to send a message to the world's elite that not everyone agrees with the rapid pace of globalization. 

"We're respectful of what New York has been through. We live here, too," says Eric Laursen, an activist with the umbrella protest group Another World Is Possible. "We're trying to be very visual and colorful and emphasize events that aren't violent in any way." 

But the organizers admit that they have no control over the violent, ski-mask-wearing vandals who inevitably accompany their protests and grab headlines by smashing windows, burning cars and engaging in street battles with police. 

David Graeber, a Yale anthropology professor and member of the anarchist group Anti-Capitalist Convergence, is already blaming police for anything that goes wrong. 

"We're not going to break anyone's heads," he said. "It's up to the police whether there's violence. If they attack us, they're the ones being violent." 

Graeber says his group plans no violence — although many anarchists believe destroying smashing Starbucks and looting McDonald's is liberating property and doesn't count as violence. 

The more mainstream demonstrators hope to distract the police, anarchists and media with a carnival-like atmosphere featuring puppets and dancers. 

"For weeks, the police have been training in riot tactics," said activist Brooke Lehman. "We've been training in samba, puppetry and street theater." 

Another World Is Possible plans to show up with huge papier-maché and cardboard figures and symbols. One will be a 15-foot tall sun that will be shielded by clouds emblazoned with the words "globalization" and "militarization." 

"We're not against a globalized economy," explains Brian Becker, spokesman for International ANSWER, the other main protest group, which espouses socialist and anti-war views. "We're against the effect of corporate globalization that enriches a small number at the expense of many." 

The city has granted permits to the main groups to protest in designated areas, but has vowed to clamp down on any illegal behavior, even enforcing an obscure 1845 state law barring groups of demonstrators from wearing masks. 

Some demonstrators may try to engage in civil-disobedience actions, such as forming human blockades around the hotel. 

The biggest protests are expected Saturday, when Another World Is Possible and International ANSWER plan successive rallies on Park Avenue near the Waldorf. 

The privately-run and -financed World Economic Forum was moved to New York this year to show solidarity with the Big Apple after the Sept. 11 attacks. It's usually held in the sleepy Alpine village of Davos, Switzerland, where last year protestors kept miles away from the meetings rampaged through the streets. 

Other gatherings to draw professional protestors in the past few years have included meetings of the World Trade Organization and the International Monetary Fund, both intergovernmental bodies, as well as the Group of Seven summit featuring leaders of the world's leading economic powers. 

In response to the protestors' complaints, the World Economic Forum has scheduled two seminars focusing on the anti-globalization movement. 

But activists point out that none of the panelists represent groups considered part of the anti-global movement. 

Also, they say that several key representatives of non-governmental organizations critical of the forum who were invited in previous years have not been invited back. 

Charles McLean, the forum spokesman, said the forum included more than 100 non-governmental organizations this year. The anti-globalization agenda, he said, "is basically anti-business." 

"The reality inside our meetings is an amazing collaborative effort of major sectors of society to help create a better world," McLean said. "But they don't want to believe it." 

The Associated Press contributed to this report.