Protests have interrupted the opening of a new US museum display which includes the plane that dropped an atomic bomb on Hiroshima in 1945.
Protesters said the exhibit should have included casualty figures
Two men were arrested after red paint symbolising blood was thrown at the Enola Gay, a World War II B-29 bomber.
Survivors of the bombing are angry that the Smithsonian's National Air and Space Museum is not displaying casualty figures from the US-led attack.
About 140,000 Japanese died in the bombing itself, and many others later.
Around six survivors and 50 peace activists visited the new annex to the museum, some holding pictures of burned victims of the blast.
Thomas K Siemer, 73, of Columbus, Ohio, was charged with felony destruction of property and loitering, while Gregory Wright of Hagerstown, Maryland, faced a misdemeanour loitering charge.
A panel of the Enola Gay was dented in the fracas.
However the museum's director, retired general John Dailey, has resisted calls for the death toll to be included.
"We don't do it for other airplanes," he told French agency AFP.
"From a consistency standpoint, we focus on the technical aspects."
The text accompanying the plane talks about its technological prowess and how it "found its niche on the other side of the globe".
"This is the second time I have seen the Enola Gay," said Hiroshima survivor Minoru Nishino, 71, who was two kilometres (miles) from the epicentre of the blast, and still bears scars.
"The first time was on August 6, 1945, when I saw it flying high
in the sky.
"When I saw the Enola Gay today, I was overcome by anger," he said.
The museum has spent months restoring the B-29 bomber for display in a giant hangar at its Steven Udvar-Hazy Center, near Dulles International Airport in Washington DC.
The Enola Gay has proved contentious for the museum before, when in 1995 portions of its fuselage, undercarriage and engines went on display as part of an exhibition about the atomic bomb, leading to protests.
Three days after the 1945 Hiroshima bombing, the US dropped another atomic bomb on the city of Nagasaki.
Within days the Japanese officially surrendered and World War II ended, although debate has raged ever since over whether the act hastened the war's end and saved thousands of lives or was one of the world's worst war crimes.