(JTA) — A Jewish family from Belgium and a French university director received anti-Semitic threats, according to reports in French-language media.

The family from Rhode-Saint-Genese near Brussels received on Tuesday a letter with a swastika and the words “dirty Jews.” The mother, identified only as Anne in an article published by La Capitale, said she did not know who might have sent the letter.

One of the family’s children attends a Jewish school but the family describes itself as secular. The family filed a complaint with police and contacted Joel Rubinfeld, founder of the Belgian League Against Anti-Semitism.

The family received the letter two days after a commemoration held on the one-year anniversary of the murder of four people, allegedly by an Islamist who is on trial and is denying his involvement in the attack, at the Jewish Museum of Belgium.

The museum’s spokesperson, Chouna Lomponda, a Belgian woman of African descent, also received a threat Tuesday on Facebook, she told La Capitale. “Stop showing and talking for Jews. It could be dangerous for you,” the text read.

In France, the director of the Technical University Institution, or IUT, in Saint-Denis near Paris, who has received multiple death threats this year, is believed to have been targeted anew by unknown individuals who sent five of his colleagues text massages reading: “You too will fall. You work for Jews.”

In addition to the messages to the colleagues of Samuel Mayol, a star of David was painted on the door of an office of a teacher at the institution, the Le Figaro daily reported Thursday.

The National Bureau for Vigilance Against Anti-Semitism, or BNVCA, on Wednesday condemned the incident in a statement and praised France’s education minister, Najat Vallaud-Belkacem, for also condemning it and classifying it as anti-Semitic.

“The anti-Semitic climate at this university has been worsening for several years,” BNVCA founder Sammy Ghozlan wrote in a statement, which blamed “anti-Israel propaganda disseminated by student bodies that are supported by the French and foreign far-left groups.”