Abubakar Shekau, the former leader of Wilayat al Sudan al Gharbi, released an audio message on YouTube on Aug. 4 in which he insisted he was still the group's leader, Africa News and AFP reported. The message comes a day after a former spokesman for the group, Abu Musab al-Barnawi, claimed he was taking over as its head in an interview in a magazine published by the Islamic State. In his message, Shekau denounced al-Barnawi as an infidel and called the leadership declaration a coup. If the voice on the recording can be verified as belonging to Shekau, its release underscores notable divisions within the group. Wilayat al Sudan al Gharbi, the militant group better known as Boko Haram, has waged a yearslong insurgency in northeastern Nigeria and carried out attacks in neighboring states, but as it has lost territory to government offensives it has increasingly relied on terrorist attacks to maintain its relevance. In deposing Shekau, the group may be trying to renew its image by presenting a new face as its head of operations.