UNITED NATIONS: A terrorism expert says three-quarters of those who become foreign fighters for the self-styled Islamic State (IS) extremist group are recruited through friends and about 20 per cent through family members.

Scott Atran, co-founder of the Center for the Resolution of Intractable Conflict at Oxford University, says research has found that "radicalisation rarely occurs in mosques" and very, very rarely through anonymous recruiters and strangers.

He said some IS recruits come from Christian families "and they happen to be the fiercest of all the fighters we find."

Atran told a meeting held Tuesday on "Foreign Terrorist Fighters" organised by the UN Security Council's counter-terrorism committee that "it is the call to glory and adventure that moves these young people to join the IS" and that "jihad offers them a way to become heroes."

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