WASHINGTON - Several thousand anti-war demonstrators marched through downtown Washington on Saturday, clashing with police at the foot of the Capitol steps where more than 190 protesters were arrested.

group marched from the White House to the Capitol to demand an end to the Iraq war. Their numbers stretched for blocks along Pennsylvania Avenue, and they held banners and signs and chanted, "What do we want? Troops out. When do we want it? Now."

Counterprotesters lined the sidewalks behind metal barricades. There were some heated shouting matches between the two sides.

Anti-war activist Cindy Sheehan told the crowd is was time to be assertive.

"It's time to lay our bodies on the line and say we've had enough," she said. "It's time to shut this city down."

Organizers estimated that nearly 100,000 people attended the rally and march. That number could not be confirmed

protesters lay down on the Capitol lawn in what they called a "die in"

to represent soldiers killed in Iraq