Hundreds of migrants have reportedly entered the U.S. through an ISIS-affiliated network and the whereabouts of over 50 of these individuals remain unknown, NBC News reported Tuesday. The Department of Homeland Security (DHS) has identified more than 400 foreign nationals who reached the U.S. from various Central Asian countries and other parts of the world as “subjects of concern” because they arrived via an ISIS-affiliated human smuggling network, according to three U.S. officials that spoke with NBC News. Over 150 of these migrants have been apprehended by U.S. authorities, but Immigration …