Hooded neo-Nazi activists disrupted a weekend ceremony to mark the liberation of Mauthausen concentration camp, Austrian police said.
Witnesses, including the Austrian head of an international Mauthausen remembrance organisation, Willi Mernyi, said a group of men dressed in black interrupted a ceremony Saturday shouting "Heil Hitler" and giving the Nazi salute before fleeing.
Survivors of the concentration camp had come to mark the 64th anniversary of their liberation from the camp's Ebensee annex.
Austria's President, Heinz Fischer, called for an end to racism as he joined some 700 people at another memorial event at the Mauthausen camp, in the north of Austria.
Around 100,000 of the 200,000 Mauthausen camp prisoners perished there during World War II.
