On 7 March 2015, Abubakar Shekau released an audio message in which he pledged allegiance to
Abu Bakr al-Baghdadi and the Islamic State. Shekau was reaffirmed as the leader of the branch in an IS video released in April 2016. Despite this, unrest among his forces caused a large force of dissidents, led by Abu Musab al-Barnawi and his stepfather Mamman Nur, to break off and relocate to
Lake Chad. On 21 June 2016,
Reuters reported Marine Lieutenant General
Thomas Waldhauser as saying "Several months ago, about half of Boko Haram broke off to a separate group because they were not happy with the amount of buy-in, if you will, from Boko Haram into the IS brand," Shekau ignored IS orders to stop using children as suicide bombers. "He's been told by ISIL to stop doing that. But he has not done so. And that's one of the reasons why this splinter group has broken off," he said, adding Islamic State was trying to "reconcile those two groups." In response, Shekau declared that he and his followers were in the right, and that "[they] will not accept any emissary except the one we can attest he is sincere and truthful for Allah and His cause". Shekau responded by declaring Abu Musab and his followers "infidels", whereupon Abu Musab accused Shekau of apostasy and, together with his brother, published a book titled ''Cutting Off the Tumor of Shekau's Kharijites''. On 27 February 2018, he was made a 'Specially Designated National' by the
United States Office of Foreign Assets Control. In March 2019, rumours began to circulate according to which Abu Musab had been replaced by Abu Abdullah Idris ibn Umar al-Barnawi as the governor of ISWAP. Neither the Islamic State's top leadership, nor members of its West Africa branch officially commented on the claims, resulting in speculations about the reported dismissal. Some argued that he had possibly been overthrown as part of an internal power struggle, while the
Multinational Joint Task Force (MJTF) claimed that he had been fired by the Islamic State's top command due to a number of defeats of his forces at the hands of MJTF. Later research by the
Crisis Group concluded that Abu Musab had stepped down after being challenged by other ISWAP senior commanders who considered him too young for a leader. The Islamic State central command never officially accepted Abu Musab's removal from his position. and
Boko Haram in 2022 Around mid-May 2021, ISWAP released an audio declaring that Abu Musab al-Barnawi had been reinstated by the IS central command as "caretaker" leader of ISWAP. With Abu Musab restored to overall command, ISWAP proceeded to
overrun Sambisa Forest, inflicting a major defeat on the Shekau faction and resulting in Abubakar Shekau's death. Al-Barnawi consequently declared Boko Haram dissolved, and Shekau dead, condemning him as "someone who committed unimaginable terrorism". Soon after, ISWAP's structure was reformed, and Abu Musab was appointed head of the ISWAP's shura (a powerful consultative assembly) and commander of Sambisa Forest. According to the
Daily Trust newspaper, he was killed in August 2021. Different accounts of his death circulated, alleging that he had either been killed by the
Nigerian Army or as a result of inter-ISWAP power struggles. It was confirmed by ISWAP sources that Abu Musab had been wounded in a clash with Boko Haram loyalists around this time, though Islamic State members did not comment on the allegations of his death. The accuracy of the claim of Abu Musab's death was questioned by
Crisis Group and
Humangle Media researchers who gathered "multiple sources" suggesting that Abu Musab had disappeared due to being promoted. According to
Humangle Media journalist Aliyu Dahiru, one source reported that Abu Musab al-Barnawi was "well and alive" as of 2022. As per these claims, Abu Musab had actually been appointed to IS central's global shura (advisory) council and was involved in coordinating IS operations beyond the
Chad Basin. This report was mirrored by interviews by
Crisis Group researchers with ISWAP members who stated that Abu Musab had been given a "larger, though unspecified, African mandate" as he was recovering from a wound. In 2023, researcher Jacob Zenn stated that "al-Barnawi [...] maintains a leading role in ISWAP, but is [no longer] the official leader". ==Publications==