Hollywood stars Sean Penn and Susan Sarandon are to join a fast protesting against the Iraq war.
Sean Penn has been an outspoken critic of the Iraq war
Protestors will each give up food for 24 hours, with the "rolling fast" due to last until International Peace Day on 21 September.
The protest has been organised by CodePink, a woman's anti-war group who are concerned at the loss of life on both sides of the Iraq conflict.
Other celebrities due to take part include Willie Nelson and Danny Glover.
Around 150 protestors began the fast outside the White House on Tuesday morning, including leading anti-war activist Cindy Sheehan, whose son died in Iraq.
Oscar-winner Penn is one of Hollywood's most vocal stars over the issue of war in Iraq.
He visited the country in 2002 and 2003, meeting politicians, visiting a water treatment plant and touring a children's hospital.