More westerners are now fighting in Syria than fought in conflicts in Iraq, Afghanistan, Somalia or Yemen, according to the officials, The New York Times reported.
The extremist militants go to Syria under the pretext of helping people but there is growing concern that they get orders from affiliates of al-Qaeda to carry out terrorist strikes al-Alam reported.
“The concern going forward from a threat perspective is there are individuals traveling to Syria, becoming further radicalized, becoming trained and then returning … to western Europe and, potentially, to the United States,” Matthew G. Olsen, the director of the National counterterrorism Center, told a security conference in Aspen, Colo., this month.
Classified estimates from western intelligence services put the number of militants from Europe, North America and Australia who have entered Syria since 2011 at more than 600. That represents about 10 percent of the roughly 6,000 foreign militants who have poured into Syria by way of the Middle-East and North Africa.
Most of the westerners are self-radicalized and are traveling on their own initiative to Turkey, where rebel facilitators often link them up with specific groups, terrorism experts say.
Many have joined ranks with the al-Qaeda-aligned al-Nusra Front, which even American officials have designated as a terrorist group.
“The scale of this is completely different from what we’ve experienced in the past,” Gilles de Kerchove, the European Union’s counterterrorism coordinator, said at the conference in Aspen.
So far, terrorism experts say, there have been no documented terrorist plots linked to European or other western fighters returning from Syria, but France’s interior minister, Manuel Valls, recently called the threat “a ticking time bomb”.
Security services across Europe are stepping up their surveillance efforts and seeking ways to make it more difficult for people suspected of being radicalized to travel to Syria.
European and other western intelligence agencies are rushing to work together to track the individuals seeking to cross the border into Syria from Turkey, though several American officials expressed frustration that Turkey is not taking more aggressive steps to stem the flow of Europeans going to fight in Syria.
