The Pentagon had on Tuesday said that it had targeted the prominent IS leader in a precision strike near the town of Al Bab and was still assessing the results.
The terror group later announced Adnani's death through its news outlet, Amaq.
He was "martyred while surveying the operations to repel the military campaigns against Aleppo", Amaq said, and vowed to avenge his death, according to media reports.
Adnani had served as principal architect of the terror group's external operations and as its chief spokesman.
"Today coalition forces conducted a precision strike near Al Bab, Syria, targeting Abu Muhammad Al-Adnani, one of IS's most senior leaders.
"We are still assessing the results of the strike, but Al-Adnani's removal from the battlefield would mark another significant blow to IS," Pentagon Press Secretary Peter Cook said.
Adnani, a senior leader in the group, has been the voice of the IS over the past few years, and has released numerous, lengthy audio files online in which he delivered fiery sermons urging followers to carry out attacks.
He was the one who called for attacks in Western countries, telling Muslims in France to attack ‘the filthy French’ in any way they could, including ‘crush them with your car’.
He has also disparaged Saudi Arabia and its influential clerics for failing to rally behind the rebels that the monarchy supports in Syria like they did decades ago in Afghanistan.
Adnani had coordinated the movement of IS fighters, directly encouraged lone-wolf attacks on civilians and members of the military and actively recruited new members, the Pentagon spokesperson said.
"The US military will continue to prioritise and relentlessly target ISIL leaders and external plotters in order to defend our homeland, our allies and our partners, while we continue to gather momentum in destroying ISIL's parent tumour in Iraq and Syria and combat its metastases around the world," Cook said.
IMAGE: IS spokesman and 'head of external operations' Abu Muhammad al-Adnani is pictured in this undated handout photo released by the US Department of State. Photograph: Reuters
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