But when officers arrived at the remote castle of Breahus, they only found a group of harmless beard aficionados.

A group calling themselves the “Bearded Villains” came together at the site with dark formal clothing, big bushy beards and the black flag of their organisation.

From a distance, their assembly was mistaken for a rally by the notorious Islamist group.

John Ekeblad, co-leader of the group, told Sweden’s Metro newspaper that the mistake illustrated the prejudices that bearded men face.

Mr Ekeblad said: “Each and every day you hear someone say you are a terrorist.”