Activist Cindy Sheehan is under arrest, for allegedly disobeying police orders during an anti-war protest outside the White House.
She was led to a police vehicle while protesters chanted, "The whole world is watching."
The California woman has used her son's death in Iraq to spur the anti-war movement.
Sheehan was among dozens of protesters who sat down on the sidewalk after marching along Pennsylvania Avenue. Police warned them three times that they were breaking the law by failing to move along, then began making arrests.
The demonstrators who were arrested cooperated with police.
A police spokesman says they'll be charged with demonstrating without a permit, which is a misdemeanor.
Sheehan and the others have been taken to a processing center to be fingerprinted and photographed. They'll be given a ticket and released.