Sousse, Tunisia - Omar Abbouda was 27 years old when he joined Jabhat al-Nusra (al-Nusra Front) to fight against the Syrian regime. Last year, he was killed in the battlefield.

"I have only learned about his travel to Syria through one of his friends," Alhadi Abbouda, Omar's father, told Al Jazeera. "He [Omar's friend] told me Omar had gone 'to do God's will and to protect those being exterminated by Bashar al-Assad," added Alhadi, who remained in touch with his son while the latter was in Syria.

Alhadi said that his son, who dropped out of his secondary education due to poor academic performance, was not particularly religious.

Thousands of young men from across Tunisia have left their home country in this way, with Sousse providing perhaps up to 1,000 of them.

Tunisia has, by some estimates, provided the largest number of foreign fighters in Syria. According to official numbers, up to April 2014, 3,000 Tunisians have joined the battlefield in Syria and Iraq. Other more recent estimates put the number at 2,500.

Some, like Omar, die there; others return. The vast majority, however, disappear.

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The touristy charm of this Tunisian city hides another, more menacing reality: The town visited by a million tourists a year, is also a source of fighters going into Syria and Iraq.

A visitor to Sousse often hears stories about youths who joined the "jihad" in Iraq and, more commonly, Syria. There are a few who are stopped before being able to leave, and perhaps end up detained, but most leave.

Within Sousse, specific neighbourhoods like Al Qalaa Al Kubra ("The Grand Castle"), Al Riyadh, Al Shabab and Hamam Soussa serve as recruitment hotpots for the stream of potential fighters.

Outside of the town quarters, districts like Herkalion, Sidi Abdelhamid and the Nafidha Housing Development fulfil a similar purpose.

These neighbourhoods have been flashpoints for violence between Islamist youth and the state authorities, witnessing events such as the storming of the South Sousse police station in 2012, in which two young Salafists were killed, and a suicide bombing last year. The public's attention has been fixated on the activities of Tunisian fighters abroad.

Anise would always claim to be in a better place than we are; he would only come back if he achieved the aim of toppling Bashar al Assad, or perhaps of dying as a martyr so that he could secure absolution for his family. - Noureddine Belaid, lawyer

Residents of these neighbourhoods share stories of how groups of six or seven youth go missing from a specific neighbourhood mosque once in a while. Days later, their families discover that they have gone to Syria or to Iraq.

Such incidents revealed what one analyst described as "a ready-made network" of young men spread across Tunisian cities that leaders of "jihadist" groups can rely on in their foreign battles.

The target, added the analyst, is always the young and born-again Muslim men, or even in some cases, those who are not religiously observant.

And the method is "religious rhetoric that combined sermonising with stories of the suffering of Muslims around the world" via the internet.

Noureddine Belaid, a legal expert, recounts the story of his 29-year-old brother Anise, who joined The Islamic State of Iraq and the Levant (ISIL) in the Syrian city of Raqqa in June.

"My brother's social circle was not exceptional. Most of his friends were not religious," said Belaid who added that his younger brother did not step outside the house for a single day, and that he must have been influenced through the internet. "Right before he left, he was glued to his computer screen."

The most common trajectory is for these young men to fly straight from Tunisia to Turkey, a country to which they can travel visa-free, before entering Syrian or Iraqi territory.

Some others also spend periods of time undergoing military training in Libya before continuing their journeys on to Syria and Iraq.

Most of the stories recounted by the town residents suggest that these youth fund their own journeys. What they cannot afford with personal funds, they either borrow or take from their families.

Alhadi said that he had no idea who recruited and financed the groups of Soussa youth who travel abroad to join ISIL and other groups. "All I know is that my son Omar financed himself, never asking for financial support."

Belaid's brother, Anise, who worked as a taxi driver, was able to finance his own travels, too, and left in a group of young men who came from across Tunisia.

"Nobody from our district, Al Qalaa Al Kubra, was in that group," explained Belaid, but "he did call us from the Turkish border, telling us he was on his way to Syria".

The Sousse volunteers, a majority of whom are between 20 and 30 years of age, tend to come from the city's working class districts, areas known not only for their poverty, but for their educational deprivation, social marginalisation but most importantly, lack of any religious education institutions.

"Anise never had friends who went to seminaries; he only did primary level, and so his motivations were not ideological, as far as I can tell."

The lawyer said that another possible motivation for his brother's departure was "perhaps some financial incentive provided by some group or another".

Many of the volunteers are also former convicts. There are, of course, exceptions, of the wealthy and educated youth joining "jihadists".

More surprising is the number of youth from Sousse who have been able to return to the country and evade prosecution by the authorities.

Representatives of the local authorities - the general commissioner and the state's regional governor - both declined to speak to Al Jazeera, because "They are not authorised to speak to the media."

Some analysts blamed the government for ignoring the social root causes for this "youth migration into Jihad land".

The poverty rate in Tunisia has for long been underestimated. According to a study by the na­tional statistics institute, it was 15.5 percent in 2010.

Political and economic uncertainty following the 2011 popular uprising has taken a toll on the employment situation and led to a decline in tourism earnings.

For its part, the government says it has done much to stop the flow of young men going to Syria and Iraq.

The interior ministry said last February that it has stopped a further 8,000 others from travelling abroad - officials also speak of 400 who returned, some of whom are in prison, others under judicial supervision.

Belaid spoke of the last time his younger brother had sent them photos home: He was standing with a group made up of various Arab and non-Arab nationalities, on Eid al-Adha.

They were all tearing up their passports. Anise wanted, he said, "to reassure us that he was fine and that trying to persuade him to come back would be futile.

"My brother would always claim to be in a better place than we are; he would only come back if he achieved the aim of toppling Bashar al-Assad, or perhaps of dying as a martyr so that he could secure absolution for his family."