Washington: Chanting "bring our troops home," tens of thousands of anti-war protesters rallied in front of the US Capitol on Saturday to pressure the government to get out of Iraq.

Veterans and military families joined some lawmakers, peace groups and actors including Vietnam war protester Jane Fonda to urge Congress and President George W. Bush to stop funding the war and pull troops from Iraq.

"When I served in the war, I thought I was serving honorably. Instead, I was sent to war ... for causes that have proved fraudulent," said Iraq war veteran Garett Reppenhagen.

"We need to put pressure on our elected government and force them to ... bring the troops home," the former sniper said to cheers from a sign-waving crowd.

Tens of thousands of people attended the rally on the National Mall, according to a park police officer.

The rally on the Mall unfolded peacefully, although about 300 protesters tried to rush the Capitol, running up the grassy lawn to the front of the building. Police on motorcycles tried to stop them, scuffling with some and barricading entrances.

United for Peace and Justice, a coalition group sponsoring the protest, had hoped 100,000 would come. They claimed even more afterward, but police, who no longer give official estimates, said privately the crowd was smaller than 100,000.

For more than two hours, speakers atop a stage that also held a flag-draped coffin criticised Bush and the US presence in Iraq before protesters marched around the Capitol.

In the crowd, a group of families of soldiers killed in Iraq held pictures of their loved ones, including one photo of a soldier in full dress uniform lying in a coffin.

More than 3,000 US troops and tens of thousands of Iraqis have been killed since the 2003 invasion of Iraq.

The protest was one of several held around the United States. In California, thousands of demonstrators took to the streets in San Francisco and Los Angeles, where several dozen people carried flag-draped, mock coffins.

Protesters also planned coordinated efforts in Washington and across the country over the next week to lobby lawmakers to take action against the war.

Asked about the protests, White House national security adviser spokesman Gordon Johndroe said Bush "understands that Americans want to see a conclusion to the war in Iraq and the new strategy is designed to do just that."

The demonstrations come amid growing efforts by lawmakers to protest Bush's plans in Iraq. The Senate Foreign Relations committee passed a resolution on Wednesday opposing the plan to send more troops.

Protesters are trying to send Bush and Congress a message that Americans do not support the war.

"I'm convinced this is Bush's war. He has his own agenda there," said Anne Chay, holding a sign with a picture of her 19-year-old son, John, who is serving in Iraq. "We're serving no purpose there."

Fonda, who was criticised for her opposition to the Vietnam War, drew huge cheers when she addressed the crowd. She noted that she had not spoken at an anti-war rally in 34 years.

"Silence is no longer an option," she said. "I'm so sad we have to do this - that we did not learn from the lessons of the Vietnam War."

More Hollywood celebrities showed up at the demonstration than buttoned-down Washington typically sees in a month.

Actor Sean Penn said lawmakers will pay a price in the 2008 elections if they do not take firmer action than to pass a nonbinding resolution against the war, the course Congress is now taking.

"If they don't stand up and make a resolution as binding as the death toll, we're not going to be behind those politicians," he said. Actors Susan Sarandon and Tim Robbins also spoke.