The protestors, calling themselves the "Enough of War Association," used 200 kilos (440 pounds) of bloody beef carcasses to make their point.

"With this dramatic scene, we wanted to protest against the war and show what the people of Iraq are actually going through," said Ernesto Sandi, one of the artists.

Police, caught by surprise by the unannounced performance, arrived at the end and were put to work cleaning up the ministry forecourt.

Costa Rica, which has had no armed forces for 50 years, has nonetheless supported Washington's stand from the outset, despite strong domestic opposition.

SPACE.WIRE