Austrian President Heinz Fischer warned against the dangers of European values being "bombed away" on Sunday at the opening ceremonies of the Salzburg Festival, the world-famous musical and drama event dedicated to art as a universal value.

Touching on the terror attacks over the last few weeks in London and Egypt, Fischer said that a Europe recovering from an earlier horror - the Nazi regime of Adolf Hitler - was ill prepared for the new threat that targets innocents everywhere.

"We never even considered that it would come to the kind of terror that murders women and children," Fischer told guests gathered for the ceremony. "But we cannot allow our European values to be bombed away."

Fischer said the arts in Austria had contributed to the defeat of the Nazi "nightmare," even if there are still "individuals who cannot differentiate between a gas chamber and a shower."

He was alluding to recent comments by John Gudenus, a far-right member of Austria's legislature who indirectly questioned the existence of gas chambers.

In separate comments, Chancellor Wolfgang Schuessel linked art to the "culture of freedom," declaring: "Europe must stand united in this question."

He called for a multidimensional Europe, adding: "Europe never was ... monocultural."