A crowd estimated by police at 25,000 converged on the White House yesterday in the biggest anti-war protest in Washington since the start of the Persian Gulf conflict. They condemned the heavy U.S. bombing campaign on Iraq that many Americans have supported.

The protesters, many of whom came from as far away as Maine and Georgia, packed much of Lafayette Square for a three-hour rally, where they heard dozens of speakers -- from a once-imprisoned member of the Black Panther Party to former U.S. attorney general Ramsey Clark. The group then paraded through downtown streets to a second rally near the U.S. Capitol. President Bush was at Camp David, Md., and congressional offices were closed.

Gathered in the unusually warm midday sun, the predominantly youthful and often angry crowd -- estimated by organizers at 70,000 to 100,000 -- included activists in a wide range of causes: black and Hispanic civil rights, Palestinian support, labor union organizing, environmental protection and gay and lesbian rights.

While many protesters listened intently to speeches and chanted slogans, others picnicked and threw Frisbees. Hawkers sold an assortment of competing leftist literature, from the Militant, a newspaper of the Socialist Workers Party, to pamphlets of the Revolutionary Communist Party.

The sponsor of the rally, the National Coalition to Stop U.S. Intervention in the Middle East, embraces supporters from federal government union locals to hard-line radical groups, such as the Marxist, New York-based Workers World Party. The coalition, which has taken a tougher line on the war than some other protest groups, has said it opposes United Nations economic sanctions against Iraq as punishment of innocent civilians, and declines to condemn Iraqi leader Saddam Hussein's invasion of Kuwait.

Several more moderate anti-war groups refused to join yesterday's protest. Some said they prefer to join one scheduled for Jan. 26 that is expected to draw large numbers of college students, religious activists and pacifists.

Yesterday's rally "may be the broadest cross section of diversity since the latter days of the Vietnam War," said Jesse L. Jackson, the District's nonvoting shadow senator, who entered the park yesterday to a deafening round of applause.

Jackson said that he did not agree with the philosophy of many of the more militant protesters in the crowd, but that he was there out of agreement with the one principle uniting them: a desire to stop the war.

The rally was a crucial test for the anti-war movement. It appeared to surge during congressional debate over giving Bush authority to use force, but seemed to falter as a wave of patriotism and pride swept the nation since U.S. pilots began bombing missions over Iraq. Iraq's missile attacks on Israel also may have added to the condemnation of Saddam.

The participants were peaceful, but there were about 10 arrests throughout the day for disorderly conduct and blocking traffic.

At one point, a group of 150 pro-Bush demonstrators, organized by the Young Americans for Freedom and college Republican groups, circled the park waving American flags and signs such as "Nuke Iraq." The group then waded into the park, and there was shoving with anti-war activists. The pro-Bush group chanted "USA, USA, USA," and the anti-war crowd replied, "Out now, out now." U.S. Park Police asked the pro-Bush contingent to leave because it lacked the required permit to demonstrate at the park.

The pro-Bush group also marched to the Iraqi Embassy and burned a tiny Iraqi flag.

Meanwhile, in Norfolk, a flag-waving rally of about 75 people in support of the U.S. military drew honks of support from motorists for a second straight day. They shouted slogans such as "We are the majority."

Brian Becker, a coordinator for the Washington rally, said the crowd was so large that a previously planned march to the downtown Martin Luther King Jr. Library was diverted to the Mall at the foot of the Capitol, where there was more space.

Becker disputed police estimates of 25,000, saying that about 500 buses brought protesters from across the country. He said each bus carried about 50 passengers, for a total of 25,000 people. He said that by "a rule of thumb," for every person arriving by bus, three come by other means, bringing the total to 100,000 or so.

Although many participants said they were elated by the crowd size, Daniel Ellsberg, the former Pentagon official turned peace activist, said the number of Americans opposing the war has shrunk since the bombing began. "They are now mesmerized by the Nintendo game" in the skies, said Ellsberg, whose necktie and gray suit contrasted with the many colorful T-shirts and jeans that were reminiscent of 1960s protests. Like other speakers, Ellsberg predicted the movement would surge again after a ground war begins and U.S. casualties rise.

Nancy Tuttle, whose son is stationed in Saudi Arabia, told the crowd her biggest fear was that there will be a ground war. "I would like to say goodbye to the soldiers who will not return," she said. Although Tuttle told the crowd that she is "pro-law enforcement" and "pro-military," most other speakers took a harder stance.

Several spoke of what they called racist and sexist policies causing large segments of society to be disenfranchised and underfunded, while the government spends hundreds of millions in the gulf. Many said they support the foundation of a Palestinian state, and condemned Israel and Zionism.

One speaker called for the creation of an "African anti-Zionist front" and the "defeat of Zionism."

Some warned of anarchy in the streets if the war is not stopped.

Casey Kasem, a Los Angeles radio host and Arab American activist, told the cheering crowd that "there was always enough money for war" but never enough money for health care and education.

The crowd laughed when filmmaker Michael Moore, who directed the documentary "Roger and Me," about General Motors, told the crowd, "I've got a job for Neil Bush." He led them in a chant of "Send Neil Bush."

Absent was D.C. Mayor Sharon Pratt Dixon, who had been scheduled to appear at a separate D.C. statehood rally organized by Jackson. Dixon canceled her appearance when plans were announced to merge the two rallies at the anti-war demonstration site in Lafayette Square. Originally an opponent of the war, Dixon shifted her position once the war began to support the troops and Bush, spokesman Paul Costello said.

There were many signs of diversity in the crowd. All were opposed to the war, but some were harsh and others gentle. Some signs called on Bush to "Please Stop the War," and others said "Our President is a Liar" and "Stop the War, No Matter What It Takes."

In one tense moment after the protesters began marching, a demonstrator attempted to burn an American flag in front of an armed forces recruiting station on 12th Street NW. David Samaria, a counter-demonstrator from New York, grabbed the flag and ran into the recruiting office.

"It's horrible that we have men and women dying in the Middle East, and {the demonstrators} don't understand the damage of what this does," Samaria said. The soldiers' morale "goes way down."

Staff writers Gabriel Escobar, Retha Hill, Mary Jordan and Saundra Torry contributed to this report.