In the first major anti-war demonstration in the nation's capital since January, several thousand protesters marched from the White House to the Capitol on Saturday, carrying signs and chanting slogans demanding an end to the war and the impeachment of President Bush.

A smaller group who support the president and the war conducted a counter-demonstration, leading to some heated confrontations. But it was a mostly peaceful affair -- until more than 190 protesters were arrested on the steps of the Capitol when they jumped barriers around the base of the building.

The rally was organized by the ANSWER Coalition, which stands for Act Now to Stop War & End Racism, and was timed to follow last week's congressional testimony by Army Gen. David Petraeus, the top U.S. commander in Iraq, and Bush's speech about Iraq on Thursday.

"We wanted to have as much impact on the congressional debate as possible," ANSWER Coalition volunteer Ann Wilson said.

The day's events began in front of the White House with a rally that included a man dressed in a Santa Claus outfit holding a sign that read "Coal for Bush and Cheney," a fake coffin for a fallen Marine and several speakers, including former presidential candidate Ralph Nader, anti-war activist Cindy Sheehan and former Attorney General Ramsey Clark.

A group called Iraqi Veterans Against the War organized a mass "die-in" in front of the Capitol to memorialize the Iraqis and American soldiers who have died since the
invasion.

About 5,000 people laid down for the die-in, said Ian Thompson, Los Angeles, one of the protest organizers, and none was arrested. But when the crowd started to get rowdier, officers pepper-sprayed many of the protesters and started making arrests, he said.

Into the early evening, protesters continued to chant, "What do we want? Peace!" in front of the Capitol.

In the morning, about a mile away, more than 1,000 people stood on the National Mall to rally in support of the war. The counter-demonstration was organized by the Gathering of Eagles -- a group of Vietnam veterans -- and the Washington chapter of the conservative group Free Republic.