A scene from the Rouvikonas march in Thessaloniki on Saturday night from a Facebook post.

Thessaloniki police will investigate whether an “anti-Zionist patrol” marching through the city center Saturday night by the anarchist collective Rouvikonas (Rubicon) amounted to an incitement to hatred and violence and whether the organizers are a criminal organization.

Rouvikonas has said the marchers, wearing black T-shirts stamped with a Palestinian flag, were protesting against increasing investments by Israeli companies in Greece. They denounced Israeli holidaymakers, including soldiers, “arriving in their thousands on cruise ships” to “take a break from raping and murdering noncombatants and children in Gaza.”

Nearly 50,000 Greek Jews, almost all from Thessaloniki, died in Nazi concentration camps. At present, just over 5,500 live across Greece, according to the Central Board of Jewish Communities in Greece, who called the marchers “an assault squad of blackshirts.”