PARIS (AP) — France is boosting security at Jewish religious sites after blank bullets were fired on a synagogue west of Paris, and amid renewed concerns about anti-Semitism around the country.

French President Francois Hollande met Sunday with leaders of the country's Jewish community, and pledged to fight extremism and anti-Semitism "with the greatest firmness."

He said that authorities "in the coming days, in the coming hours" will increase security at Jewish religious sites so they won't be subject to the kind of attack that targeted a synagogue in the Paris suburb of Argenteuil on Saturday night.

A representative of the synagogue says the building was targeted with about eight blank bullets and services were cancelled. The representative, who spoke on condition of anonymity because a police investigation is under way, said no one was hurt in the incident.

It came hours after police carried out raids across France on Saturday targeting a suspected jihadist cell of young Frenchmen recently converted to Islam. DNA on a grenade that exploded last month at a kosher grocery store led them to a member of the cell, who was killed in a shootout with police Saturday.

Officials said he had been under surveillance since last spring — around the time a French Islamist radical went on a shooting rampage against a Jewish school and French soldiers, killing seven people.

A leading French Muslim organization, the CFCM, denounced the synagogue attack. It said in a statement Sunday that it "assures the French Jewish community of its support and fraternal solidarity in the face of all attacks that target its members and institutions."