PARIS — Two high school classmates, both French Muslims, headed off to Syria this month instead of going to school. They were located, brought home — one fetched by his father — and are now being investigated on terrorism-linked charges.
The unfolding drama of the teenagers, aged 15 and 16, highlights how Syria has become a magnet for a vulnerable fringe of young Muslims in the West. It is among a small wave of cases that are putting French authorities, and some families, on edge.
The bloody 3-year-old conflict in Syria has drawn thousands of Muslims to join the ranks of battalions trying to topple the regime or other fighting groups looking to conquer the region in the name of Islam.
French authorities say that more than 600 French have gone to Syria, are plotting to go, or have returned, and more than 20 French have been killed in fighting. As of mid-January, a dozen French adolescents were in Syria or in transit, according to authorities.
Many of the alleged would-be jihadists are clearly amateurs.
‘‘He’s a victim. He’s not a terrorist,’’ said the father of the 15-year-old before his son was preliminarily charged with links to terrorism — a rare event for a minor. ‘‘He never touched a weapon,’’ said the father, calling his son’s trip ‘‘an error of youth.’’
As the boys from France’s southern Toulouse region were questioned by a judge, the trial of three French Muslims caught heading to Syria was concluding in another wing of the Palace of Justice in Paris.
The three, ages 21 to 26, had made a long list of purchases, from camouflage hoods and vests to gun holsters and night vision goggles. But their trip in 2012 ended before they boarded the plane, aborted by their arrest at a French airport.
French intelligence is in close contact with western nations, from European neighbors to the United States and Australia, to try to spot would-be jihadists and track those who return and present a potential danger. French Interior Minister Manuel Valls plans to present a series of measures to President Francois Hollande in coming weeks aimed at stemming the tide of French Muslims to Syria.
France feels especially vulnerable. It has the largest Muslim population in Western Europe, estimated at 5 million, and Syria, once under French rule, is familiar to some citizens.
Alain Chouet, a former intelligence director at France’s DGSE spy agency, said youth looking for a cause are attracted by Internet battle videos or recruitment forums, media attention, and easy access from Turkey, a vacation destination for many French people.
The western support for the Syrian National Coalition fighting Assad may have further legitimized Syria as a destination.
‘‘It is considered a just cause [because of] the position of the French, Europeans, and Americans,’’ Chouet said. Not all would-be jihadis follow the ins and outs of the war, but ‘‘what people understand is that this revolution is just.’’