“Although no one has so far claimed responsibility, we must assume that there was a xenophobic motive,” Dresden police chief Horst Kretschmar said.

German Interior Minister Thomas de Maiziere said the mosque attack was “all the more scandalous” because it happened on the eve of the 10th annual meeting of the German Islam Conference.

Police linked the explosion at the congress centre to celebrations set to take place next week in Dresden marking the 26th anniversary of German unification, which is to be attended by German President Joachim Gauck.

“We have now switched to crisis mode,” Kretzxchmar said, as police deployed to guard the city’s two mosques and an Islamic cultural centre.