About 5,000 European fanatics have traveled to Syria and Iraq with between 15 to 20 per cent dying on the battlefield.
Up to 35 percent have returned some with ‘specific missions’ and 50 percent remain in the battle theatre, which amounted to between 2,000 and 2,500 Europeans.
Belgium expressed concern last month that terrorists were increasingly returning to Europe as US-backed coalition forces drive ISIS terrorists from territory in the terror group’s self-declared caliphate across Syria and Iraq.
As many as 1,750 may have returned, based on the percentages listed in the report which EU counter-terrorism coordinator Gilles de Kerchove will present to EU interior ministers on Friday.
The report said there were two types of ‘foreign terrorist’ returning.
‘Those in the majority that will drift back, and those who will be sent back on specific missions, which are of most concern,’ the report warned.
It said even some European women and children born or raised in the so-called caliphate declared by ISIS terrorists in Iraq and Syria could pose a security threat as they may have been radicalized.
Without giving figures, it said some returnees have been convicted and serving prison sentences, while others are being monitored and some are free in their communities.
It recalled that foreign terrorists who have returned to Europe have staged both foiled and successful attacks, including the slaughter in Paris in November last year and this year’s bombings in Brussels in March.