SAN FRANCISCO — Thousands of people called for a swift end to the war in Iraq as they marched through downtown on Saturday, chanting and carrying signs that read: "Wall Street Gets Rich, Iraqis and GIs Die" or "Drop Tuition Not Bombs."

The streets were filled with thousands as labor union members, anti-war activists, clergy and others rallied near City Hall before marching to Dolores Park.

As part of the demonstration, protesters fell on Market Street as part of a "die in" to commemorate the thousands of American soldiers and Iraqi citizens who have died since the conflict began in March 2003.

The protest was the largest in a series of war protests taking place in New York, Los Angeles and other U.S. cities, organizers said.

No official head count was available. Organizers of the event estimated about 30,000 people participated in San Francisco. It appeared that more than 10,000 people attended the march.

"I got the sense that many people were at a demonstration for the first time," said Sarah Sloan, one of the event's organizers. "That's something that's really changed. People have realized the right thing to do is to take to the streets."

In the shadow of the National Constitution Center and Independence Hall in Philadelphia, a few hundred protesters ranging from grade school-aged children to senior citizens called on President Bush to end funding for the war and bring troops home.

Marchers who braved severe wet weather during the walk of more than 30 blocks were met by people lining the sidewalks and clutching a long yellow ribbon over the final blocks before Independence Mall. There, the rally opened with songs and prayers by descendants of Lenape Indians.

"Our signs are limp from the rain and the ground is soggy, but out spirits are high," said Bal Pinguel, of the American Friends Service Committee, one of the national sponsors of the event. "The high price we are paying is the more than 3,800 troops who have been killed in the war in Iraq."

Vince Robbins, 51, of Mount Holly, N.J., said there needed to be more rallies and more outrage.

"Where's the outcry? Where's the horror that almost 4,000 Americans have died in a foreign country that we invaded?" Robbins said. "I'm almost as angry at the American people as I am the president. I think Americans have become apathetic and placid about the whole thing."

In New York, among the thousands marching down Broadway was a man carrying cardboard peace doves. Some others dressed as prisoners, wearing the bright orange garb of Guantanamo Bay inmates and pushing a person in a cage.