As chairman of the Annasr mosque, Mimoun Aquichouh personally knows a number of young men who left the small Belgian city of Vilvoorde to wage jihad in Syria.

They worshipped at his mosque on a quiet street in the former industrial city just north of the capital Brussels as they fought their own personal struggles before finding the path of jihad, much to Aquichouh's dismay.

Their stories offer a glimpse into the minds of some of the estimated 325 young Muslims from Belgium and around 3,000 from across the European Union who have joined the Islamist militant cause in Syria and Iraq.

"I know some of them, those who frequented the mosque just before leaving," Aquichouh told AFP in the offices of his mosque.

The place of worship has no minarets and stands behind a grey-stone building on a street of terraced houses.

"They were young people with no diploma, who had problems with the law, who had problems with society and who did not work," he said.

"These were young people who had a background of drugs and theft."

He recalled one young man who struggled with both a drug problem and confusion over his cultural identity in a Flemish city with a large community of Moroccan origin.

"Sometimes you see him dressed 100 percent in European clothes, and sometimes you see him in (traditional) long clothing. He was lost," Aquichouh said.

He was waging a "jihad al-nafs," or personal struggle to fight his "bad desires," and found the power to do so in religion, the Muslim community leader said.

- Sense of injustice -

Per capita, Belgium has produced the highest number of so-called foreign fighters in the EU, an estimated 325, according to officials. European capitals have been clutching at responses for stemming the flow of jihadists to Syria and Iraq.

Aquichouh said the lure of Islamist militant propaganda was another factor.

He cited an Internet video showing how the militants had four-wheel drive cars, were armed and were masters of their own destiny with plenty of land and money.

"What they forgot to say in the propaganda is that behind all that there are bombs, there are tanks, there is a dirty war with people killed and seriously wounded," he said.

The propaganda also plays into a sense that "Muslims are unjustly treated in the world," he said.

He said he never had the chance to intervene to stop anyone because "these were young people I never thought would leave."

Vilvoorde mayor Hans Bonte, who also knows some young Muslims who became jihadists, said the process of radicalising young men and even young women can take only a few months.

Bonte, who was invited to the United States last month to share his views on radicalisation, said community leaders must act fast to prevent jihadist recruiters from isolating and preying on vulnerable young people.

The community response, he said, must involve teachers, youth workers, social workers, sports clubs staff and others to spot signs of radicalism. Then police or even a favourite teacher or friend can intervene to stop them, he told AFP.

In one success in May, he said, police and social workers managed to stop two girls from Vilvoorde, one 14 and the other 15, from leaving nearby Brussels airport for Syria via Turkey.

Parents may at first be happy to see their children suddenly stop drinking alcohol and start praying at the mosque, study Arabic and wear traditional clothes, and in the cases of their sons, grow beards.

But these may be the first signs of radicalisation, he said.

- Real enemies -

"There is a point in the radicalisation process that anyone who has a different opinion than they have are real enemies," Bonte said.

"And against real enemies you can do anything you want," he added.

The mother of one young man who left for Syria told the mayor how she suddenly found her son threatening to kill her if she prevented him from travelling there.

Bonte said that in the last two years at least 27 Muslims, including two young women, have left Vilvoorde to wage jihad in Syria and Iraq, an unusually high number for a city of 40,000 people.

Aquichouh thinks the number is no more than 20 jihadists out of 5,000 Muslim families in Vilvoorde.

In Brussels, the Christian mother of a young man who converted to Islam when he was a teenager and whom she believes became a jihadist in Syria, is distraught over her son's choice.

"Our children are victims and are not terrorists. The terrorists are the leaders," said the woman who declined to be named and who does not know how her son radicalised.

"I felt him demoralised sometimes...He wanted to live in the land of Islam," she said.