Polish police are investigating the desecration of a Jewish cemetery in northeastern Poland.

Monika Krawczyk, the CEO of the Foundation for the Preservation of Jewish Heritage in Poland, said vandals spray-painted swastikas and anti-Semitic images and slogans on graves, a Holocaust memorial and the entrance to the Jewish cemetery in Wysokie Mazowieckie near Bialystok on Sunday night.

One of the slogans read “Here is Poland – not Israel,” which, according to Krawczyk, is a slogan used by Polish neo-Nazi groups. No Jews live in Wysokie.

The cemetery had been devastated in World War II. It was restored in 2006 and, protected by a fence, is maintained regularly by the Foundation.

Krawczyk noted that there had been several anti-Semitic vandal attacks on Jewish sites in northeastern Poland in 2011. But, she said, “We had not seen an anti-Semitic attack on such a scale this year.”