Washington The US Defense Department on Tuesday confirmed the death of a key Islamic State (IS) leader known as "Omar the Chechen" as a result of injuries sustained during an airstrike conducted in Syria on March 4. The Pentagon confirmed what until now was only a possibility, because although it had informed that he was a target in the attack, it was not known for certain whether he had died or not, EFE news reported. The attack also would have killed 12 other jihadi fighters near the town of Al Shadadi, in the Al Hasaka province bordering Turkey. Known as "Omar the Chechen", Abu Omar al-Shishani was born in Georgia and served in the armed forces of his country during the short war with Russia in 2008. "Shishani is a battle-tested leader with experience who had led IS fighters in numerous engagements in Iraq and Syria," said Pentagon Press Secretary Peter Cook. "His potential removal from the battlefield would negatively impact IS' ability to recruit foreign fighters especially those from Chechnya and the Caucasus region - and degrade IS' ability to coordinate attacks and defence of its strongholds like Raqqa, Syria, and Mosul, Iraq," Cook added. It is believed that Shishani began fighting in rebel brigades of the Syrian civil war in 2012 and that one or two years later he joined the IS, where he held prominent military positions including "minister of war", the Pentagon added.