LA GRANDE-MOTTE, France — About 200 police officers hunted on Saturday for a man who tried to set fire to a synagogue in the southern French city of La Grande-Motte, Prime Minister Gabriel Attal said, adding that authorities would be ruthless with antisemitism.

A policeman was slightly injured when a gas bottle exploded as police secured the site of the attack on Saturday morning, Attal said.

“The person (attacker) set fire to several entry doors to the synagogue and several cars,” Attal…