Vandals daubed a swastika on one of the slabs that make up the Holocaust memorial in downtown Berlin, police said Saturday. A security service worker found the symbol on Friday morning, and authorities ordered it removed, police said in a statement. There was no immediate word on who might have been responsible. The memorial, a vast field of more than 2,700 gray slabs situated close to the Brandenburg Gate in the heart of the German capital, opened to the public in May 2005. It is freely accessible around the clock. Although the slabs are covered with an anti-graffiti coating, swastikas have been reported at the site on a number of previous occasions.