STEVE INSKEEP, HOST:
Authorities in Europe are concerned about their countries being used as incubators for terrorist attacks. You will recall that some 9/11 attackers had lived in Germany. Two Boston Marathon bombing suspects had links to Russia. Even peaceful Belgium is now asking just who's living there and what they do when they go abroad. Teri Shultz reports.
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TERI SHULTZ, BYLINE: Members of the al-Qaida-linked al-Nusra Front in Syria exchange words amid gunfire and alarm a nation far away from the warzone.
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HICHAM EL-MZAIRH: They communicate in Flemish, in accent of Flemish from Antwerp.
SHULTZ: Antwerp, Belgium. That's Hicham el-Mzairh, one of Antwerp's city councilors active in the Muslim community.
EL-MZAIRH: That was actually the evidence that they are there.
SHULTZ: They are there, along with hundreds more European jihadists. Part of a growing trend of teenagers, lifelong Muslims or converts, answering al-Nusra's videotaped pleas for help in fighting the Assad. Here, el-Mzairh translates.
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SHULTZ: Many devastated parents are also scanning these extremist videos, hoping they'll see their kids alive, hoping they'll come back. Public safety officials are less eager for the homecomings of potentially hostile individuals with terrorist training. Europol director Rob Wainwright.
ROB WAINWRIGHT: We're concerned about the extent to which they present a safety threat to citizens of the European Union upon their return.
SHULTZ: Concerned for good reason, says el-Mzairh. This is not the war on terror we know, he says. It's more dangerous - fought with warriors we thought we did know.
EL-MZAIRH: They are our kids. They are born here, they talk the language and talking about Beyonce or - but the day after talking about jihad in Syria. You can't see it coming.
SHULTZ: But el-Mzairh feels officials could have done more to counter this problem in advance. He's been warning the city since 2005 that radical extremists were recruiting in parks and schools, that imams needed more training in moderate interpretations of Islam to guide young people.
EL-MZAIRH: If you don't give them answers about their religious questions, you give them actually an emptiness where they seek for themselves answers. And they find them on Internet, they find them with those groups.
SHULTZ: In the Brussels suburb of Schaerbeek, where roughly half the population is Muslim, Mayor Bernard Clerfayt is taking action after two seemingly well-adjusted 16-year-olds in his own kids' school shocked everyone by turning up in Syria.
Clerfayt banned certain groups from distributing free food outside a train station because he learned the meals came with radical Islamist propaganda. Some people criticized him for doing that, but one group in particular, Clerfayt says, thanked him.
MAYOR BERNARD CLERFAYT: The great majority of Muslims are happy I did it. They are happy I protect their kids from this form of radicalism.
SHULTZ: The European Union is trying to help too, putting eight million euros per year into a new grassroots human alarm system called the Radicalization Awareness Network. It connects and trains teachers, mental health workers and others who may be able to pick up on warning signs before vulnerable youngsters get on a plane, believing their path to paradise somehow goes through Syria. For NPR News, I'm Teri Shultz in Brussels.
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INSKEEP: It's NPR News. Transcript provided by NPR, Copyright NPR.