Police estimated 100,000 anti-war demonstrators hit the streets in San Francisco on Sunday, filling 12 large city blocks stretching from the waterfront to city hall.

Demonstrators had postponed their event one day so as not to infringe on the city's popular Chinese New Year parade.

"Finally it seems there is a worldwide movement saying this is obviously a catastrophic path we're on," said Deborah Hoffmann, 55, part of a group of Arab and Israeli women. "And now everybody is out in the streets."

In Denver, about 300 people waving U.S. flags and holding signs proclaiming "war is bad, evil is worse" gathered Sunday in support of using force against Iraq.

"I support our president and I support my sons. This is the only option," said Pam Pearson, 49, whose two sons are in the Navy. "I'd rather force Sadaam out than have to play by his rules."

Saturday's protests against a possible U.S.-led attack on Iraq drew more than one million demonstrators in Rome and tens to hundreds of thousands in other cities around the world.

In New York, demonstrators poured into the streets north of the United Nation's headquarters, filling in police-barricaded zones in an area more than 20 blocks long and two blocks wide as singers and actors energized the banner-waving crowd. NYPD Commissioner Raymond Kelly said about 100,000 people were in the crowd

"Peace! Peace! Peace! Let America listen to the rest of the world — and the rest of the world is saying: Give the inspectors time,"' South Africa's Bishop Desmond Tutu said after an ecumenical service at a church across from the United Nations.

"Just because you have the biggest gun does not mean you must use it," Martin Luther King III told the demonstrators as he stood before an enormous banner reading: "The World Says No To War."

More than 250 people were arrested in New York; most of the 257 arrests were for disorderly conduct and other minor violations that mostly resulted in tickets to appear in court, police said. Five people were arrested on felony charges and 53 on misdemeanors.

"I think it went well. It was orderly," Kelly said. "We facilitated people's ability to make their opinions known."

The New York rally was opened by singer Richie Havens performing "Freedom," just as he did 34 years earlier at the original Woodstock Festival. Speakers included Susan Sarandon, Harry Belafonte and Pete Seeger.

Some demonstrators, however, voiced their support for the possibility of U.S. military action. About 1,000 demonstrators gathered on Manhattan's West Side, where 41-year-old George Sarris held a sign reading "Bomb Iraq."

Police in Colorado Springs, Colo., fired tear gas at protesters, sending at least two to a hospital, and made arrests after the demonstrators blocked a major thoroughfare near an Air Force base.

In Los Angeles, activist actors Martin Sheen and Mike Farrell and director Rob Reiner protested with thousands of chanting marchers who filled four blocks of Hollywood Boulevard. Police estimated the crowd size at 30,000.

"None of us can stop this war ... there is only one guy that can do that and he lives in the White House," said Sheen, who plays a fictitious U.S. president on NBC's The West Wing.

Global Day of Dissent

In London at least 750,000 protesters sought to pressure Prime Minister Tony Blair, who has been Europe's biggest supporter of the stern U.S. policy toward Iraq. Police have called the rally the city's largest demonstration ever.

"I feel they should take more time and find an alternative, and not see the only solution to the problem in bombarding the country," said Maria Harvey, 58, a child psychologist, who said she hadn't marched since the protests against the Gulf War in 1991.

Blair said Saturday it would be "an act of humanity" to depose Saddam Hussein and insisted signs of Iraqi cooperation with weapons inspectors were suspect.

In Spain, several million people turned out at anti-war rallies in about 55 cities and towns across the country, with more than 500,000 each attending rallies in Madrid and Barcelona. Spanish police gauged the Madrid turnout at 660,000.

Berlin had up to 500,000 people on the streets, and Paris was estimated to have had about 100,000.

In Syria, a nation on the front line if war comes, some 200,000 protesters marched through Damascus. In Bulgaria, Athens, South Korea, Australia, Malaysia and Thailand, demonstrations attracted thousands, while the crowds were in the hundreds or less in Bosnia, Hong Kong, Indian-controlled Kashmir and Moscow.

Crowds were estimated at 70,000 people in Amsterdam -- making the rally the largest Netherlands demonstration since anti-nuclear rallies of the 1980s -- 5,000 in Capetown and 4,000 in Johannesburg in South Africa, and 2,000 in Dhaka, Bangladesh.

Najjah Attar, a former Syrian cabinet minister, accused Washington of attempting to change the region's map. "The U.S. wants to encroach upon our own norms, concepts and principles," she said in Damascus. "They are reminding us of the Nazi and fascist times."

Braving biting cold and snow flurries in Ukraine, some 2,000 people rallied in Kiev's central square. Anti-globalists led a peaceful "Rock Against War" protest joined by communists, socialists, Kurds and pacifists.

Natalya Mostenko, 45, was one of several people in Kiev carrying a portrait of Saddam. "He opposes American dictatorship and so do I," she said.

In the Bosnian city of Mostar, about a hundred Muslims and Croats united for an anti-war protest — the first such cross-community action in seven years in a place where ethnic divisions here remain tense despite the 1995 Bosnian peace agreement.

"We want to say that war is evil and that we who survived one know that better than anyone," said Majda Hadzic, 54.

Several thousand protesters in Athens, Greece, unfurled a giant banner across the wall of the ancient Acropolis — "NATO, U.S. and EU equals War" — before heading toward the U.S. Embassy.

Police fired tear gas in clashes with several hundred anarchists wearing hoods and crash helmets, who broke from the otherwise peaceful march to smash store windows and throw a gasoline bomb at a newspaper office.

In the Greek port of Thessaloniki, an estimated 10,000 people protested.

About 2,000 demonstrators rallied in Sofia, the Bulgarian capital. In Moscow, 300 people marched to the U.S. Embassy, with one placard urging Russian President Vladimir Putin to "be firmer with America."

Six hundred people rallied in downtown Hong Kong, as did 50 or so in Almaty, Kazakhstan.

Demonstrators clogged a downtown park in Seoul, South Korea, to chant and listen to anti-war speeches.

"I am scared, but the Iraqi people must be more scared than I am. I share their fear," said Eun Kook, a 23-year-old student planning to go to Iraq. "My mission is to sympathize with the Iraqi people and to tell the world that we oppose war."

The day of protest began in New Zealand, where thousands gathered in cities across the country. Over Auckland harbor, a plane trailed a banner reading "No War — Peace Now," at the America's Cup sailing competition.

Between 3,000 and 5,000 people marched through a suburb of Canberra, the Australian capital, to protest government support for U.S. policy. Australia has already committed 2,000 troops to the Persian Gulf for possible action.

In Tokyo, where 6,000 protested on Friday, about 300 activists gathered near the U.S. Embassy. One placard depicted a U.S. flag emblazoned with a swastika.

Many demonstrators in Asia expressed skepticism that Iraq posed a threat to world security, saying instead that President Bush's policy against the Middle Eastern country was a way to extend American control over oil reserves.

"We must stop the war as it is part of the United States' plot for global domination," protest organizer Nasir Hashim told 1,500 cheering activists outside the U.S. Embassy in the Malaysian capital of Kuala Lumpur.

Other groups gathered in Bangkok, Taipei, and Singapore. In Bangkok, as many as 2,000 people marched with banners to the U.S. Embassy. The crowd included Thai Muslims and Westerners, and several Buddhist monks and nuns.

The Associated Press contributed to this report.