Analysing Shekau’s audio message, Mansur Liman, editor of BBC’s Hausa Service said that the voice was that of Shekau, but that in the audio recording, Shekau seemed more subdued than in previous ones.

“His delivery was slow and steady, in contrast to his habitually theatrical performances. It is also interesting that this was an audio recording, rather than one of the slickly produced videos Boko Haram has been releasing, rather like those of its Islamic State allies. It could be that the pressure is starting to tell,” said Liman according to the BBC report.

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.