Aug. 29 (Bloomberg) -- Thousands of protesters marched past New York's Madison Square Garden, where the Republican National Convention starts tomorrow, to show their opposition to the Iraq war and President George W. Bush.

An estimated 400,000 people participated, according to the organizing group, United for Peace and Justice. Police wouldn't give a figure, said Doris Garcia, a police spokeswoman. Mayor Michael Bloomberg called them a ``sizable crowd.''

``Tomorrow the Republican Party will meet just a few short blocks from here, and they will send their message of war and greed and hate,'' said Leslie Cagan, the protest group's national coordinator. ``We want the immediate end of the occupation and we want the troops brought home now.''

Amid concerns about terrorism, police are prepared for dozens of demonstrations this week along with an influx of 50,000 delegates, party officials and press, prompting the city's largest and most expensive security operation ever.

The demonstrators marched about 2 miles through midtown Manhattan starting shortly before noon, with the last contingent stepping off almost three hours later. Those at the front included Democratic U.S. Representative Charles Rangel of New York and filmmaker Michael Moore, whose ``Fahrenheit 9/11'' documentary presented a view critical of Bush.

Influx

Police arrested 116 people at or near the march as of 5:10 p.m., Garcia said. Bloomberg, who attended several events for Republicans during the day, said, ``United for Peace and Justice has acted responsibly, and so have most of the marchers.''

New York is mobilizing virtually its entire 37,000-member police force for the convention, reinforced by federal law enforcement agencies, according to Police Commissioner Raymond Kelly. Bloomberg said Friday the city's net cost for security would be as much as $15 million. The U.S. government is paying $50 million of the city's expenses.

A Bush campaign spokesman, Steve Schmidt, associated the demonstrators with Bush's Democratic Party opposition. ``For most Americans those Democrats out on the street today represent a viewpoint that is outside of the mainstream,'' said Schmidt. He also said the protesters were ``exercising their First Amendment right.''

Coffins

Activists including the actor Danny Glover and members of groups such as Military Families Speak Out and the National Council of Churches joined Cagan, Rangel and Moore at the head of the march, behind the banner ``We Say `No' to the Bush Agenda.'' Marchers waved placards saying ``Bush Lies, Who Dies?'' and ``Defend Immigrant Rights, Protect Civil Liberties.'' Some carried American-flag draped coffins on their shoulders.

``I paid a very high price for this speech -- I paid with my son's life,'' Fernando Suarez del Solar of California told reporters before the start of the march. Del Solar, whose son, Jesus, died while fighting in Iraq in March 2003, represented Military Families Speak Out. ``Bush lied, and who died? My son, and 972 other beautiful boys and girls,'' he said.

Tony Esposito, 50, a retired stock trader from New York said he voted for former Republican Presidents Richard Nixon and Ronald Reagan and was now a registered independent voter.

``This administration is so obviously wrong on so many levels, I felt it was very important to be a part of the dissenting voice,'' Esposito said. ``Fighting terror is a quiet endeavor -- you do it with brains, you do it with allies. I think Bush is fighting terror exactly the wrong way.''

Marchers held banners for other causes, such as civil liberties, the environment and education.

Delegate Responds

Foy Jolley, a delegate from Cheyenne, Wyoming, said he had no fear of the protesters or of being in New York.

``I will not be deterred by a threat of hostile action here,'' said Jolley, 64, a retired department chief of the Wyoming state capitol police and a U.S. Air Force Vietnam veteran. Speaking in the lobby of the Sheraton New York Hotel & Tower on Broadway, Jolly said he supports Bush ``150 percent.''

Jolley said he refused to bring his wife, Cheryl, a Democrat, with him. ``I said, `I am not paying your way here to protest against my president.'''

At 34th Street and Seventh Avenue, one block from the Garden, a line of helmeted police stood shoulder to shoulder behind portable metal barricades as marchers passed by chanting ``No more Bush.'' At midday, the temperature in the city was 86 degrees Fahrenheit (30 degrees Celsius), with humidity making the temperature feel like 90 degrees, according to the Weather Channel Web site.

Central Park

Shonna Carter, a United for Peace and Justice spokeswoman, said the estimate of 400,000 participants was based on 80 full blocks of marchers who lined up to participate. That would make the crowd one of New York's biggest since an anti-nuclear arms rally in 1982 drew more than 500,000 people, according to police estimates.

``Despite all the hype and paranoia, you had an extremely orderly, peaceful demonstration,'' said Doug Muzzio, a professor of political science at New York's Baruch College who observed the march. ``The relationship between the protesters and police was respectful on the one hand and professional on the other.''

The organizing group was twice denied a permit to hold a post-march rally on the park's Great Lawn. At the march's end at Union Square, organizers with megaphones urged people to disperse, thanking them for coming and telling them they could take the subway wherever they wanted, without specifically mentioning the park.

Several thousand milled around the Great Lawn in the late afternoon, some chanting peace slogans, under the watch of police. City officials said they wouldn't arrest people who went to the park as long as they didn't break any laws, such as using megaphones or loudspeakers.

Police arrested 25 demonstrators at various locations yesterday. With today's arrests, the total related to the convention stood at 427 after the march ended.

The mayor is founder and majority owner of Bloomberg News parent Bloomberg LP.

To contact the reporter on this story: Josh P. Hamilton in New York at jphamilton@bloomberg.net.

Last Updated: August 29, 2004 17:48 EDT