London:The US's most wanted terrorist "Omar the Chechen" -- considered the Islamic State's defence chief -- was confirmed dead by the terrorist group, media reports said on Thursday. Months after the US claimed they killed Omar al-Shishani, the IS said its "minister of war" was "martyred" in the Iraqi city of Shirqat, south of Mosul, as he was trying to "halt the military campaign" against the city. Military officials had been offering up to $5 million for information that would lead to his removal from the battlefield. The Pentagon had claimed that he died from his wounds in a US airstrike in Syria back in March. News of Shishani's death came from the IS's media arm -- Amaq news agency, which had earlier denied reports that he died in March. Shishani, 30, known for his distinctive red-tinted beard, was born into a mixed Georgian-Chechen family. He served the Georgian army and fought against Russian troops before being discharged two years later for medical reasons. He was arrested in 2010 for weapons possession and spent more than a year in jail. He left Georgia in 2012 for Istanbul and later Syria. Shishani volunteered to join the IS in 2013 and pledged his allegiance to Baghdadi. Shishani was repeatedly described as a capable commander by US intelligence sources, and was reportedly consulted by the IS leader Abu Bakr al-Baghdadi on key military movements, as the terrorist group expanded its reach, earning the unofficial moniker of "Minister of War", RT news reported.