German Chancellor Angela Merkel has denounced attacks on synagogues and other Jewish cultural institutions in Germany, her spokesman reported on Friday.

On Wednesday, German police arrested more than a dozen men in 3 cities suspected of setting Israeli flags ablaze, damaging a synagogue and starting a fire at a Jewish memorial site, with authorities warning there could be more demonstrations over the conflict between Palestinian militants and Israel in Gaza.

“Our democracy cannot tolerate such displays of anti-Semitism,” government spokesman Steffen Seibert said, noting that Israel enjoyed the German government’s full solidarity.

Earlier on Friday, Israel’s Ambassador in Berlin, Jeremy Issacharoff, called on Germany to provide protection for the Jewish community.

Issacharoff told broadcaster ARD that “the conflict in the Middle East has nothing to do with the Jewish community here. I would urge the German authorities to do all they can to ensure the safety of the community.”