ISWAP is an offshoot of the Boko Haram insurgent group that has been fighting against the Nigerian armed forces for 12 years. The two militant groups later turned on each other.
The conflict between the insurgents and Nigeria’s armed forces, which has also spread to neighbouring Chad and Cameroon, has left about 300,000 dead and millions dependent on aid.
“I can authoritatively confirm to you that Abu Musab is dead,” Lucky Irabor, the chief of defence staff, told reporters at the presidential villa in Abuja, without elaborating.
The Daily Trust, a northern Nigerian newspaper, reported that al-Barnawi had died in late August, citing unnamed sources. It said different sources had given different accounts of how the ISWAP leader had died.
Al-Barnawi was the third leader of an Islamist insurgent group in West Africa to die this year, after Boko Haram’s Abubakar Shekau in May and Adnan Abu Walid al-Sahrawi of Islamic State in the Greater Sahara (ISGS).