Shekau is known for kidnapping over 200 schoolgirls in Chibok in 2014. He appeared in series of video in which he threatened to sell the girls as slaves.
The deputy who has replaced Shekau is interested to negotiate with Nigerian government according to Idriss Deby, the president of neighbouring Chad.
On Tuesday, a bomb killed at least 47 people and wounded dozens more in a cattle market at village of Sabon Gari in Borno state. Two days before that, jihadists shot dead four people and abducted five more in the same area.
It is not the first time that reports have emerged claiming Shekau's downfall. Reports from the Nigerian military and media have declared him dead on several occasions, although experts also believe that the various videos that have appeared purporting to be him sometimes feature lookalikes.