After another act of vandalism, this one at a Holocaust memorial in Thessaloniki, whose Jewish population was decimated by the Nazis during World War II, the World Jewish Congress said Greece needs to get tougher on anti-Semitic attacks.

The monument at Aristotle University marked the loss of Jewish students during the war and was sprayed with blue paint and hate slogans. It also designates the site of an old Jewish cemetery destroyed by the Nazis in 1942, part of the grounds where the school sits.

Only 12 days earlier, red paint was thrown at the Holocaust memorial in central Thessaloniki and the flowers surrounding it were destroyed. A month before that, vandals had destroyed nine marble Jewish tombstones in an Athens cemetery.

World Jewish Congress President Ronald S. Lauder expressed that “The consternation we feel following such a cowardly desecration is only compounded by the fact that this is not an isolated incident,” the Jerusalem Post reported.

“We will continue to stand shoulder to shoulder with the Jewish Community of Thessaloniki and in Greece to combat racism, antisemitism and hatred under difficult circumstances,” he said.

The latest act came as Greece joined 21 other countries sponsoring a statement to the United Nations Human Rights Council denouncing anti-Semitism and Lauder urged Greece to “follow through on its commitment to combating antisemitism, and treat these incidents with utmost severity, concern, and action.”

Before WWII, Greece, and especially Thessaloniki, was home to a large and active Jewish community. Greece’s second-largest city is a diverse and cosmopolitan metropolis but even today the Jewish community is under assault, now from the ultra-far right Golden Dawn party accused of using neo-Nazi tactics.

Israeli President President Reuven Rivlin visited the Holocaust monument in Thessaloniki during a state visit in February and spoke out against renewed anti-Semitism, extremism, racism and neo-Nazism.