LUNEL, France » When this picturesque southern French town of just 25,700 people first learned late last year that six local Muslims had been killed fighting for Islam in Syria, accounting for 10 percent of the total number of French killed there, the right-wing mayor quietly asked the head of the local mosque for help.

"I need you and you need me to stop this," the mayor, Claude Arnaud, recalled telling Lahoucine Goumri, who was president of Lunel’s Al Baraka mosque at the time. "We agreed he would make a statement."

He did. But instead of condemning the surge of young recruits, Goumri told local news media that the policies of President Francois Hollande were the main culprit and complained that it was not his job to denounce the jihadis when nobody protested French citizens who traveled to Israel to help the army "kill Palestinian babies."

"This is their choice," Goumri was quoted as saying at the time by the newspaper Midi Libre. "It is not for me to judge them."

In the wake of last week’s attacks by terrorists in and around Paris that killed 17 people, Lunel is still struggling to fathom how such a small town, nestled in the sun-splashed Languedoc wine-growing region, has come to earn its dubious distinction as a breeding ground for jihadis.

Investigators have long noticed that particular towns or even streets tend to spawn unusually high numbers of jihadis, a phenomenon thrown into relief Thursday when the police killed two suspected militants in the eastern Belgian town of Verviers, from which about a dozen residents are said to have gone to fight in Syria.

But Lunel’s situation shows how difficult it will be to identify, never mind halt, the forces pushing France’s young Muslims toward extremism, even as the authorities face pressures to uproot extremist networks that have sent more than 1,000 French citizens to Syria and Iraq and to take the potential threat of informal clusters of radicalized youths more seriously.

The mayor, noting that the number of Lunel residents who traveled to Syria is perhaps no more than 20 in all, said his town had been unfairly put in the spotlight because of its "bad luck" at having so many be killed in quick succession.

But after initially playing down the problem, he is now scrambling to figure out what went wrong and ensuring that those who went to Syria and managed to stay alive do not return after "being trained to shoot and to cut throats. This is an immense danger."

Anti-terrorism prosecutors in Paris are investigating whether Lunel has been infiltrated by a jihadi cell or underground group like the Buttes-Chaumont network, which once sent fighters to battle U.S. troops in Iraq and which was the starting point for at least one of last week’s Paris gunmen, Chérif Kouachi.

Arnaud said he doubted the existence of a network in Lunel, believing that those who left were just a group of school friends who decided to take up jihad after being influenced by radical websites as well as peer and family pressures. The six killed in Syria — ranging in age from 19 to 28 — all seem to have known one another.

"We are all trying to understand but feel completely out of our depth," he said, flicking through a file prepared by the municipal police with the names and brief biographies of each of the deceased. All were born in France, he said, and none had previously attracted attention of the local police.

One of those who left, Raphael Amar, is the son of a Jewish engineer. He grew up in a comfortable home with a swimming pool, played the guitar and loved Led Zeppelin. In July, after traveling to Paris for a job interview, the 22-year-old convert vanished, calling home a few days later to announce that he had gone to Syria, not to fight but to do relief work. He was killed just three months later in clashes at Deir al-Zour, a city in the east of the country.

The same battle also claimed the lives of two of his school friends from Lunel, a town that in the medieval era and later attracted a large number of Jewish immigrants, particularly from Spain, but is today about a third Muslim.

"From almost one day to the next, Raphael rejected everything," said a person close to the family, who asked not to be named. "It was as if he had joined a sect."

In an effort to get to the bottom of what happened, the family has hired a lawyer to file civil charges "against X," a French procedure that allows a plaintiff to gain access to official inquiries and to seek redress for a crime committed by a defendant not yet identified.

Many here have turned their attention to Goumri and Al Baraka. The mosque, in contrast to a place of worship frequented mainly by immigrants from Turkey, was attended at one time or another by all of those who went from Lunel to Syria.

On Jan. 6, a day before the Paris attack on the satirical newspaper Charlie Hebdo, Pierre de Bousquet, the state’s senior representative, or prefect, for the Hirault region, which includes Lunel, made a visit to the town and said he was "preoccupied" by Al Baraka.

"There is clearly a risk of a fundamentalist takeover," he told Midi Libre, stressing that the French state also had a responsibility "to show to young people that the republic has not forgotten them, to show that there is a place for them, a future."

Amar’s family believes the mosque leadership did not urge worshippers toward jihad but that it did allow activists affiliated with Tabligh Jamaat, a secretive Islamic revivalist group that originated in India, to spread its ideas, which German and other European intelligence services have characterized as sometimes leading to extremism.

A 2010 study by France’s Institute for Islamic Studies the Muslim World said the mosque was "close to Tabligh," but it raised no concerns about any tilt toward violence.

France’s surging National Front, a far-right party that won 37 percent of the vote in Lunel in elections in May for the European Parliament, believes it is past time to take action against the mosque.

"It is very simple: This mosque should be shut down," Guillaume Vouzellaud, a local National Front leader, said, calling for an investigation of its activities and an end to national policies that he said allowed immigrants to "impose their own values and culture" instead of forcing them to assimilate and "show a strong will to be French."

On Sunday, in a vote that had been scheduled before the attacks in Paris, congregants at the mosque chose a president to replace Goumri, who decided not to seek another term.

But the urgent issue remains finding out "why, at a certain moment in this town, which has social and economic problems but no worse than in many other places, so many young people left for Syria," said Philippe Moissonnier, a Socialist Party member of the local council.

"Did they leave because of the mosque?" he added "We don’t know. But there was clearly some sort of catalyst or accelerator."

Taher Akermi, a counselor at a state-funded youth and cultural center who knew most of the six killed in Syria, said he was baffled by their departure for jihad. Young Muslims in Lunel, he said, face a host of problems, including 40 percent youth unemployment, "but just because you don’t have work does not mean you are going to blow yourself up or do jihad."

He said that he noticed an increased religious zeal among some of those who went to Syria but that this did not cause undue concern.

Amar, who had celebrated Passover as a boy, was once an enthusiastic participant in musical and other events at the center. But he eventually stopped attending and started spending much of his free time at the mosque, upbraiding others for insufficient devotion.

Yet, Akermi said he had no inkling that he and the others might join jihad in Syria. "This has been my work for 25 years, and I feel this as a failure," he said. "What am I doing here?"

The authorities have set up a hotline staffed to help parents spot and cope with children who might be drifting into extremism. They also hope that the election of the new mosque president, Rachid Benhadj, a shop owner who declined to be interviewed, will usher in a new era of cooperation marked by a greater appreciation of the real dangers posed by radical Islam.

But Benhadj has yet to declare publicly where he stands, and some worshippers at the mosque insist there is no need for a new direction.

The imam at the mosque, who speaks only Arabic, condemned the Paris attack in his sermon Friday. At a central traffic circle, a small replica of the Statute of Liberty, erected in 1889 for the 100th anniversary of the French Revolution, has been draped with a banner reading "Je suis Charlie."

But worshippers at Lunel’s mosque expressed little of the solidarity found on the streets of Paris. "What we did before we will continue," said one, who declined to give his name.

Another, complaining of "stigmatization" by non-Muslims as he brusquely ordered a reporter to leave the mosque’s "private property," asserted the Paris attacks were not carried out by Muslims but by the French state so as to discredit their faith.

All the same, local officials are still waiting to see what the new mosque president might bring.

"We don’t know what he is like," said Pierre Souljol, the town’s first deputy mayor. "He seems like a normal local resident. We just hope he will help stop this conveyor belt that is sending young people to their deaths as cannon fodder."

Andrew Higgins, New York Times