Thousands of motorcycle riders from across the United States have come to Washington for an annual rally on Memorial Day weekend.
Participants in "Rolling Thunder" gather to draw attention to the cases of U.S. military personnel who may be prisoners of war or missing in action from all wars, and to other issues affecting military veterans.
The rally is part of the U.S. Memorial Day observance that pays tribute to fallen American service members.
The holiday weekend is also seen as the unofficial start of summer in the United States, with people often celebrating with parades, picnics and other outdoor activities.
The rally takes its name from "Operation Rolling Thunder" - the constant bombing of North Vietnam in 1965.
Many of the bikers who will ride their motorcycles Sunday from the Pentagon to the Vietnam Veterans Memorial in Washington are veterans of the Vietnam war.