SARCELLES, France (JTA) – Shortly before their synagogue became shrouded by tear gas and smoke, 100 Jews wielding baseball bats and clubs were singing the French national anthem in front of the synagogue’s heavy metal gate.

They had gathered outside the main synagogue in this Paris suburb Sunday to defend it against a predominantly Arab mob of 200 men who had gathered nearby with sticks and stones, setting garbage cans aflame and chanting “Slaughter the Jews.”

The Jewish defenders were not singing for the rioters. Their performance of “La Marseillaise” was intended as a gesture of gratitude toward the 100 police officers clad in anti-riot armor that prevented the mob from approaching.

Unable to reach the Grand Synagogues of Sarcelles, some of the rioters smashed shop windows in this poor suburb where tens of thousands of Jews live amid many Muslims. They torched two cars and threw a firebomb at a nearby, smaller synagogue, which was only lightly damaged.

“We sang to thank them, but also to remind them and ourselves that we are equal French citizens entitled to safety,” said Eliyahu, a member of France’s Jewish Defense League, or LDJ, who agreed to be identified only by his first name.

It was the ninth synagogue attack in France since Israel launched Operation Protective Edge in Gaza two weeks ago. To Eliyahu and many other French Jews, the attacks have contributed to a growing realization that, despite the extraordinary efforts of French authorities to protect them, French Jews need to rely mostly on themselves for their defense.

“The cops are here now, but it’ll be just us and the Arabs tomorrow,” said Serge Najar, a local community leader.

French authorities have been vigorous in their condemnations of recent attacks, with President Francois Hollande vowing not to allow violence in the Middle East to spill over into the streets of France and Prime Minister Manuel Valls promising to severely punish anti-Semitic attacks.

But while they are grateful for the government’s backing, many French Jews lack confidence in its ability to protect them. Bernard Cazeneuve, the French interior minister, temporarily banned protests against Israel last week out of concern for public order, but that ban was ignored by thousands who staged unauthorized protests anyway.

“I want to have every confidence that the authorities can ensure the community’s safety, but sadly, I do not — not fully,” said Yves Victor Kamami, a member of the executive board of CRIF, the umbrella group of French Jewish communities. Kamami suggested the government hire security firms to help protect synagogues during periods of unrest.

In this climate, there appears to be growing support for LDJ, a controversial group with a history of vigilantism and violence that has been central to recent efforts to fight back against mobs attacking French synagogues.

Martine Cohen, a sociologist who specializes in French Jewry, said LDJ’s activity has increased due to “the escalation of anti-Semitic attacks that target Jews, supposedly for Israel’s actions,” though she stressed that LDJ remains a small movement that pales in comparison to the threat posed by pro-Palestinian rioters.

“I used to tell my grandsons to focus on the studies and stay out of trouble, but now I sent them to join the LDJ and defend our synagogues against the scum,” says Victor Sofer, a barber who works in Paris’ heavily Jewish 10th arrondissement.

“The Arabs own the streets now,” said Sofer. “We need make them lose the appetite for messing with us if we’re to survive here. LDJ is our Iron Dome.”

LDJ’s leader, a man who identified himself only as Amnon, told JTA he too is sensing a change in attitudes toward his group.

“The leadership of the Jewish community, who live in nice houses far from Sarcelles, used to condemn us as troublemakers,” Amnon told JTA as he surveyed an unauthorized demonstration against Israel on Saturday near the Gare du Nord train station. “But that has been gradually changing.”

Indeed, just a few months ago, CRIF cautioned Jews not to take the law into their hands after a suspected LDJ reprisal against Arabs in the streets of Paris. But last week, CRIF defended the actions of young Jewish fighters, many of them from LDJ, who on July 13 were in a massive street brawl with anti-Israel protesters outside the Synagogue de la Roquette in Paris.

“The actions of the young men in front of the synagogue were justified,” CRIF President Roger Cukierman told JTA. “The LDJ has its problematic aspects, but now is not the time to discuss them. We have more pressing issues.”

Three Jews were wounded in the fight at the Synagogue de la Roquette, in which 30 young Jewish men from LDJ and other groups fought off 200 rioters while six police officers protected the 150 worshipers inside. For 15 minutes, the young Jews kept the mob from reaching the synagogue doors until French riot police arrived on the scene. Videos of the clashes show both LDJ members and anti-Israel rioters hurling bottles and even chairs at one another.

“We are, at this point, in need of our community’s young activists to complement police security, there’s no doubt,” said Joel Mergui, president of the French Consistoire, the community’s central body for religious services. “Their presence at La Roquette may have prevented a disaster.”

At the Saturday demonstration at Gare du Nord, Amnon, who is in his 50s, communicated by telephone with members of LDJ and other groups. His colleagues were conducting surveillance at the rally to provide early warning in case protesters headed to a synagogue.

“This way, we can mobilize within minutes and save lives, like at La Roquette” Amnon said.

One of the LDJ members at the rally was a bald man in his 50s wearing a Bluetooth earpiece and a heavy black coat despite the oppressive heat. The coat was padded for protection against stabbing and for intimidation. “For all they know I could be carrying,” he said.

By telephone, the man whispered instructions to a young Jewish woman elsewhere at the demonstration.

“Stay safe, take pictures discreetly and only if you see criminal activity,” he said. “And remember to shout ‘Free Palestine.’”