The mayor of Venice on Thursday condemned a reported attack over the weekend on an American Orthodox Jewish couple by assailants who shouted “Free Palestine” as a “serious and unacceptable act.”

Italian news agency AGI said three assailants, believed to be of North African origin, were apprehended.

Venice is home to what is widely considered the oldest Jewish Ghetto in Europe. The lagoon city “is and must continue to be an open, welcoming, and safe city, where mutual respect is the foundation of civil coexistence,” Mayor Luigi Brugnaro said in a statement Thursday.

He praised law enforcement agencies for having quickly intervened to identify those responsible, with the help of video surveillance cameras.

The Jewish Community of Venice said in a statement that the attack was just the latest antisemitic act it has registered. It condemned it as a “cowardly and despicable act,” and warned that it called into question Venice’s tradition as a welcoming city.