– European leaders are warning against a rise in anti-Semitism in the region after some protests over Israeli military action gave way to racist slogans.

French President François Hollande called on protesters to maintain calm Tuesday during a march in Paris following attacks in the past week on Jewish institutions, while German Interior Minister Thomas de Maiziere said racism against Jews would not be tolerated.

“The state of Israel’s right to exist can under no circumstance be called into question,” he said. “There must be just as little room in the German public for open or concealed hatred of Jews.”

Israel’s incursion into the Gaza Strip and fighting that has killed more than 600 people, the overwhelming majority of them Palestinians, has unleashed protests in Europe. Some of the rallies have included anti-Semitic chanting and even turned violent, drawing condemnation from lawmakers across the political spectrum.

French Foreign Minister Laurent Fabius and his German and Italian counterparts, Frank-Walter Steinmeier and Federica Mogherini, issued a news release Tuesday in Brussels condemning the anti-Semitic “statements, demonstrations and attacks” as having “no place” in Europe.

“The challenge will be to translate the clear words into equally clear actions,” said David Harris, executive director of the American Jewish Committee. “Threats to Europe’s Jews threaten Europe’s core values and very future.”

Defying a ban in France on pro-Palestinian marches, about 7,000 people demonstrated in Paris’ Barbes district Saturday, prompting police to use tear gas and leading to the arrest of 44 people.

The next day in Sarcelles, just north of the French capital with both Jewish and Muslim communities, youths vandalized Jewish shops and burned parked cars. Military police guarded a synagogue as 18 people were arrested trying to attack the house of worship.

“This is a first; we have never seen such hate, such a willful attack on the community,” Sarcelles Mayor Francois Pupponi said. “It’s very worrying.”

The outbreak of violence comes weeks after French police arrested Mehdi Nemmouche as the prime suspect in the murder of three people at a Jewish museum in Brussels.

Hollande has repeatedly warned against the risk of importing the Israeli-Palestinian conflict into his country, which has Europe’s largest Jewish community.

In Berlin, police pledged to take action against demonstrators using an anti-Semitic slogan following criticism that authorities didn’t initially react when a number of protesters used the chant.

“There is no place in our country or our city for anti-Semitism,” Berlin’s state interior minister, Frank Henkel, said. “Germany as well as Berlin have a historical responsibility to protect the state of Israel.”