The profiling of the foreigners has started to determine whether or not they were working in cahoot with Boko Haram insurgents, who are fleeing their former stronghold.
The military has blocked all known entry and exit points to Sambisa Forest to hem in the remnants of the insurgents.
According to a military source, the identities of the foreigners and their missions in Sambisa Forest will not be revealed untill after a thorough screening has been completed.
Intelligence officers are profiling the foreigners, who are suspected to be providing “back-up” for Boko Haram.
The source said: “”In the last one week since we launched massive operations in Sambisa Forest, we have arrested over 40 foreigners.
“We will come up with the details later after the profiling of these suspects. They are all being debriefed. But we discovered that there were so many foreigners in the midst of Boko Haram.