Thousands of anti-Israel protesters gathered in Paris Saturday, defying a police ban on demonstrations that was announced Friday following a clash with riot police last weekend that trapped hundreds of Jews in two synagogues

The demonstrators were protesting against Israel’s Operation Protective Edge, using the event to also chant against the French government and French President Francois Hollande in particular, for issuing the ban, France 24 reported.

The demonstrators threw rocks and bottles at anti-riot squads, which responded with tear gas lobbied into the streets.

Several protesters climbed onto a building under construction, burning an Israeli flag. Others waved a Palestinian flag from atop a street sign.

Other protesters put up banners reading “Palestine Will Live” and “Israel Assassins” in front of Montmartre’s famed basilica.

Pro-Palestinian demonstrators hold banners reading: "Palestine will live" and "Israel assassins," in front of the Sacre Coeur basilica at Montmartre in Paris, Saturday July 19, 2014. (photo credit: AP Photo/Remy de la Mauviniere)

Pro-Palestinian demonstrators hold banners reading: “Palestine will live” and “Israel assassins,” in front of the Sacre Coeur basilica at Montmartre in Paris, Saturday July 19, 2014. (photo credit: AP Photo/Remy de la Mauviniere)

The ban, which Hollande had said was to preserve “public order” following violence after similar marches, applied only to Paris. Thousands turned out in several other French cities for authorized demonstrations against the ongoing Israeli offensive in Gaza.

Protesters burn an Israeli one on a rooftop where is hung a placard reading "zionism = nazism" as they gather near the Barbes-Rochechouart aerial metro station prior to the departure of a demonstration, banned by French police, in Paris on July 19, 2014. (photo credit: AFP/Francois Guillot)

Protesters burn an Israeli one on a rooftop where is hung a placard reading “zionism = nazism” as they gather near the Barbes-Rochechouart aerial metro station prior to the departure of a demonstration, banned by French police, in Paris on July 19, 2014. (photo credit: AFP/Francois Guillot)

Hollande, speaking from west Africa, has said that he is seeking to avoid “importing” the Middle East conflict into France.

Participants who insist on holding the rally “at all costs will bear the responsibility” for it, he said earlier Saturday. However, he added, “this isn’t going to stop other forms of expression.”

Authorities say organizers who defy the ban will face a six-month prison term and 7,500-euro fine.

Meanwhile Belgian police were concerned that unauthorized demonstrations would take place in Brussels and Antwerp on Saturday.

Representatives from Belgium’s Jewish and Muslim communities joined together on Friday to call for good relations to be upheld between religious communities.

A police official said Wednesday that a demonstration planned for Saturday would be banned because of “the serious risk of disruption of public order that such a protest could engender, in a context of heightened tension.” The official, who wasn’t authorized to be publicly named, spoke on condition of anonymity.

French Jewish leader Roger Cukierman described the current tensions as the worst in decades.

During other rounds of conflict in recent years, when anger mounted in France, he said, “We heard death to Israelis. Now we hear death to Jews.” He said anti-Arab discrimination in France feeds the anger.

He called for calm, and acknowledged that forbidding protests can be “delicate, because there is freedom of expression.”

Meanwhile, in London, tens of thousands took part in a march from British Prime Minister David Cameron’s office to the Israeli embassy, carrying placards reading “Stop the bombing, free Palestine”, “Stop Israeli state terror, join the socialists” and “End Israeli apartheid,” while also chanting slogans, such as “Israel is a terrorist state,” and calling for a Palestinian state from the Jordan River to the Mediterranean Sea.

In recent days, protests against Israel’s operation against Hamas have raged in major cities throughout the world, including Cairo, Istanbul, Cape Town, Berlin, New York and Washington, some of which turned violent.

In Istanbul, police warded off hundreds of rioters who attempted on Thursday to storm the Israeli embassy building. Demonstrators in Ankara and Istanbul also hurled stones at several compounds where Israeli officials reside. Calls for the destruction of the Jewish state were heard in both Turkish cities. Police responded by firing tear gas canisters and water cannons at the crowds. Israel decided Friday to pull some of its diplomatic staff out of Turkey in the wake of the protests.

AP contributed to this report.