The Anti-Defamation League (ADL) has expressed deep concern over the closing of a Jewish community center in Sweden after series of troubling anti-Semitic incidents and threats to members of the community.

According to press reports, the community center of Umea was vandalized with swastikas and the message, “We know where you live,” causing members of the city’s Jewish community to fear for their safety.

“This situation simply cannot be acceptable in today’s Sweden,” said Jonathan A. Greenblatt, ADL CEO. “This incident should be a catalyst to ensure that every Jewish community in Sweden both is secure and has a sense of security to live openly and freely as Jews.”

In a letter to Sweden’s Prime Minister Stefan Löfven, ADL raised concerns that many Jewish institutions across Sweden have insufficient security measures and urged the government to do more to ensure that these institutions are adequately protected nationwide.

ADL had recently discussed communal security issues with the Council of Swedish Jewish Communities.

“While Umea’s Jewish community may be small in number, we respectfully urge you to consider the magnitude of this event,” Mr. Greenblatt wrote in the letter.

“A Jewish community center closed due to anti-Semitic threats, fear in the community, and lack of confidence that the authorities will protect them. Such a situation cannot be acceptable in Sweden today. This local crime and its consequence should be a national issue, as it speaks to the heart of Sweden’s democratic values.”

According to ADL’s 2014 Global 100 Poll, only four percent of Sweden’s adult population holds anti-Semitic attitudes, one of the lowest levels of anti-Semitism in the world.

In a recent letter headlined “Is it Time for Jews to Leave Europe?”, World Jewish Congress (WJC) President Ronald S. Lauder cited recent violent attacks against Jews.

Current polls indicate that a majority of European Jews do not feel comfortable wearing clothing or jewelry that identifies them as Jews.

“Make no mistake…the safety and security of European Jewry is in Jeopardy,” wrote Lauder.