More than 25,000 foreign fighters have traveled to join militant groups such as al-Qaeda and Islamic State (IS), according to a UN report.
Along with some 22,000 foreign fighters in Syria and Iraq, there were also 6,500 in Afghanistan and hundreds more in Yemen, Libya, Pakistan and Somalia.
Experts have said that the flow of foreign fighters is “higher than it has ever been historically”.
At a meeting of the 15-member Security Council chaired by President Barack Obama in September, the experts were asked to report within six months on the threat from foreign fighters joining ISIS, which has declared a caliphate in Syria and Iraq, Nusra Front in Syria and other al Qaeda-linked groups.
Fighters from at least 100 countries have travelled to areas such as Iraq, Syria, Libya and Pakistan.
The report states that this poses an immediate and long-term threat to global security.
“For the thousands of (foreign fighters) who traveled to the Syrian Arab Republic and Iraq … they live and work in a veritable ‘international finishing school’ for extremists as it was in the case in Afghanistan during the 1990s,” the experts wrote in their report submitted to the council late this month. “Those who eat together and bond together can bomb together.”
Al Qaeda founder Osama bin Laden found refuge in Afghanistan in the 1990s, where the militant group ran training camps.
The report also said an unintended consequence of defeating ISIS in Syria and Iraq could be the scattering of violent foreign fighters across the world.
There are also 6,500 fighters in Afghanistan and hundreds in Yemen, Libya and Pakistan, the report says.
It adds that a high number of foreign fighters have come from Tunisia, Morocco, France and Russia.
There has also been an increase in the number coming from the Maldives, Finland and Trinidad and Tobago.
The report called for greater intelligence sharing between nations to help identify foreign fighters.
