FILE - In this undated file photo released by a militant website, which has been verified and is consistent with other AP reporting, militants of the Islamic State group hold up their weapons and wave its flags on their vehicles in a convoy to Iraq, in Raqqa, Syria. IS, the ultra-extremist group responsible for some of the worst atrocities perpetrated against civilians in recent history, is on the verge of collapse. The group that brutalized residents living under its command for more than three years is fighting to hang on to remaining pockets of territory in Iraq and Syria, besieged by local forces from all sides. (Militant website via AP, file)

Russia has been the No. 1 source country of foreign fighters for the Islamic State, according to a new report by a private security-intelligence firm, which also claims that thousands of the terror group’s fighters have returned to their home countries after losing territory in Syria and Iraq.
The report released Tuesday by the New York-based firm The Soufan Group said “there are now at least 5,600 citizens or residents from 33 countries who returned home” in a situation that “represents a huge challenge for security and law enforcement entities” around the world.
“As the so-called Islamic State (IS) loses territorial control of its caliphate, there is little doubt that the group or something similar will survive the worldwide campaign against it so long as the conditions that promoted its growth remain,” the report stated. “Its appeal will outlast its demise, and while it will be hard to assess the specific threat …