Islamic State group says spokesman killed in Syria

This undated militant image provided by SITE Intel Group shows Abu Muhammed al-Adnani, the Islamic State militant group's spokesman who IS say was "martyred" in northern Syria. The IS-run Aamaq news agency said Tuesday, Aug. 30, 2016 that al-Adnani was "martyred while surveying the operations to repel the military campaigns against Aleppo," without providing further details. (SITE Intel Group via AP) (The Associated Press)

This undated image posted online Wednesday, Aug. 31, 2016, by supporters of the Islamic State group on an anonymous photo sharing website, shows Abu Muhammed al-Adnani, IS's spokesman and chief strategist, who laid out the blueprint for the extremist group's attacks against the West. The IS-run Aamaq news agency said Tuesday, Aug 30, 2016, that al-Adnani was killed while overseeing operations in northern Syria, without providing further details. (Militant Photo via AP) (The Associated Press)

The Islamic State group says its spokesman has been "martyred" in northern Syria.

The IS-run Aamaq news agency said Tuesday that Abu Muhammed al-Adnani was "martyred while surveying the operations to repel the military campaigns against Aleppo," without providing further details.

IS has released several audio files online in which Adnani, a senior leader in the group, delivers fiery sermons urging followers to carry out attacks.

The extremist group has suffered a string of defeats in recent weeks, including in Syria's northern Aleppo province, where Turkish troops and allied Syrian rebels drove IS out of the border town of Jarablus last week.