Unidentified vandals on Monday desecrated the Holocaust memorial in Thessaloniki as officials in the northern Greek city prepared to pay their respects to survivors, Jewish officials said. The perpetrators daubed a plaque in memory of the 50,000 Jews killed by Nazi Germany with the words \"That\'s a lie\", a Star of David and the swastika, the head of the country\'s Jewish council Kis, David Saltiel, told AFP. The defilement was the second after the memorial opened in the 1990s. The city\'s memorial service for the about 30 survivors still living in Greece\'s second city was said to be the first in 65 years. Thessaloniki\'s new mayor Yannis Boutaris, who defeated the conservative candidate in local elections last year, is seeking to highlight the city\'s multicultural and religious past at the crossroads of the southern Balkans. While regretting an \"increase in anti-Semitic attacks as Greece is hit by an economic and social crisis\", Saltiel welcomed the condemnation of the desecration by the government and the city. \"Those guilty must be arrested and condemned,\" he said.