Chanting ''No more war," demonstrators trudged down snow-whipped Tremont Street and up Park Street past the State House and then looped back to the Common, streaming peacefully past scores of police officers who lined the parade route, clutching batons.

Before the march, Cindy Sheehan -- the mother of a soldier slain in Iraq whose vigil outside President Bush's ranch in Crawford, Texas, this summer helped galvanize the antiwar movement -- rallied the crowd.

Like many speakers, Sheehan seized on the rising death toll in Iraq, as well as the indictment this week of a vice presidential aide on charges of perjury, obstruction, and making false statements, as fresh evidence that the war was immoral and based on deception.

''We were all finally pleased that one of the liars was exposed," Sheehan said, referring to the indictment of I. Lewis Libby Jr., as the crowd applauded. ''But how many more liars do we have to go after in this administration?"

With that, the throng -- teenagers with faces swathed in bandanas, teachers, nurses, union organizers, and longtime peace activists -- shouted in unison: ''All of them!"

''To prison," a woman's voice chimed in.

A group called The October 29th Coalition organized the demonstration. Sponsors included college antiwar groups, socialist organizations, Iraq Veterans Against the War, and City Councilor Felix Arroyo, who also participated.

Polls show a majority of Americans now oppose the war, but some of the demonstrators were saddened that the audience, dominated by veteran activists, did not seem to reflect the breadth of that majority.

BU student Kasia Zabawa, holding an American flag, confronted antiwar protesters yesterday on the Common.

Some worried that the virulently anti-administration tone of the demonstration might have scared off some opponents of the war.

One demonstrator carried a sign that read, ''Bush Wants Your Children For Cannon Fodder," and another that accused the president of causing the terror attacks on Sept. 11, 2001.

Some of the musical performers sang antiwar anthems that could have played on any coffeehouse stage. But others led the demonstrators in chanting choruses laced with expletives against the president and the war.

Sheehan, whose son, Casey, was killed in April 2004 after insurgents ambushed his unit in the Sadr City section of Baghdad, said it was important to use strong language to oppose the war. She mentioned a woman who had once e-mailed her after she cursed the Bush administration.

''She said, 'Cindy, don't you want to use a little nicer language, because you know there might be people sitting on the fence that you offend,' " Sheehan told the crowd. ''And do you know what I said? I said, 'Damn it, why is anybody on that fence still?' "

''A lot of people will come up to me and say, 'My country right or wrong,' " Sheehan added later. ''And you know what I say? When my country is wrong, it is so wrong, and it is mandatory for us to stop it, to stop the killing, to stop the people in power."

The message resonated with Ernest Johnson, 60, of Abington, who held a handmade sign that read, ''Iraq War Is Offensive."

''It's like Vietnam," said Johnson, a manager at a Brockton foundry that makes manhole covers. ''I don't think it's going to stop until people get into the streets."

Jill Hallisey, 50, a nurse practitioner from Jamaica Plain, said yesterday's rally was her first. Her reason to attend: ''The 2,000 dead," she said.

''It just kind of hit home how many people, and plus this latest indictment -- people can't ignore it," she said. ''I know they try to do everything they can to change our attention to something else, but you really can't ignore it when the administration is outright lying."

A copy of the Boston police deployment plan for the protest, obtained by the Globe, called for 323 officers -- a sizable contingent but less than the 558 who patrolled the city during the Red Sox season-ending series against the Yankees at Fenway Park and the 334 who patrolled during the American League Championship Series last year, when an Emerson College student was killed.

Along the route of yesterday's march, officers were visible on horses, bicycles, and on foot. Police afterward reported no arrests.

During the march, some demonstrators stopped outside a conference at the Tremont Street Baptist Church that sought to encourage gays and lesbians to become heterosexuals. Some protesters chanted ''Shut it down," and one waved a sign that read, ''Thank God we're gay."

''They have the right to be homosexual and we have the right to walk away from homosexuality," said Mike Haley, host of the conference called ''Love Won Out" and director of public policy for Focus on the Family, a conservative group. ''We respect that people have to make that decision for themselves."