epa04436298 A frame grab from video released by the Federal Bureau of Investigation on 07 October 2014 shows an alleged Islamic State militant holding a hand gun as he claims to be inside the Syrian 17th Division Military Base just outside Al-Raqqah, Syria. In the video he threatens the execution of captured Syrian military personnel who he claims are digging their own graves. The FBI is asking for the public's assistance in identifying the militant, who speaks with a North American accent, and any other people who may have or are planning to travel overseas to join in the fighting. EPA/FEDERAL BUREAU OF INVESTIGATION / HANDOUT EDITORIAL USE ONLY / NO SALES