The U.S. military community is reportedly trying to determine whether a recent U.S. airstrike in Syria killed a top ISIS leader known as Omar “the Chechen” Al-Shishani, officials told CNN on Tuesday. The strike in question took place Friday in al-Shaddadi—a strategic city previously held by ISIS forces before the Syrian army launched an offensive. Al-Shishani, the leader who may have been killed, has had a $5 million reward on his head from the U.S. State Department, and is considered one of the militant group’s strongest commanders. "[al-Shishani] is a battle-tested leader with experience who had led ISIL fighters in numerous engagements in Iraq and Syria," a Pentagon spokesperon said. "His potential removal from the battlefield would negatively impact ISIL's ability to recruit foreign fighters—especially those from Chechnya and the Caucus regions—and degrade ISIL's ability to coordinate attacks and defense of its strongholds like Raqqah, Syria, and Mosul, Iraq."