The leader of Nigeria's Boko Haram denied he had been killed or ousted as chief the jihadist group in an audio recording released Sunday attributed to him by security experts.
In the eight-minute Hausa-language message, Abubakar Shekau denied claims by Chadian leader Idriss Deby that he had been replaced and calls the president a "hypocrite" and a "tyrant".
"It is indeed all over the global media of infidels that I am dead or that I am sick and incapacitated and have lost influence in the affairs of religion," he says in the recording released on social media.
"It should be understood that this is false. This is indeed a lie. If it were true, my voice wouldn't have been heard, now that I am speaking."
Deby declared on August 12 that efforts to combat neighbouring Nigeria's Boko Haram jihadists had succeeded in "decapitating" the group and would be wrapped up "by the end of the year".
Deby told reporters in the capital N'Djamena Boko Haram was no longer led by the fearsome Shekau and that his successor, whom he named as Mahamat Daoud, was open to talks.
"Gratitude be to Allah and with his help, I have not disappeared. I am still alive and I am not dead. And I will not die until my time appointed by Allah is up," Shekau says in the message.
The SITE Intelligence Group verified the authenticity of the message, and an AFP correspondent with extensive experience of reporting Boko Haram said it exactly resembled Shekau's voice in previous recordings.