A man purporting to be the leader of Nigerian Islamist militant group Boko Haram, Abubakar Shekau, denied the jihadist group has been pushed out of its stronghold in the Sambisa forest.

President Muhammadu Buhari on Saturday said Boko Haram’s last enclave in the forest, a former game reserve in northeast Nigeria, had been captured in the “final crushing” of the group.

Reuters has been unable to independently verify that the area was captured.

“We are safe. We have not been flushed out of anywhere,”

the man identifying himself as Shekau said in a video seen by Reuters on Thursday.

“If you indeed crushed us, how can you see me like this? How many times have you killed us in your bogus death?” he added in the 25-minute video during which he spoke in the Hausa language and Arabic.

Nigeria’s military has in recent years said it has killed or wounded Shekau on multiple occasions.

Such statements have often swiftly been followed by video denials by someone who says he is Shekau, but poor footage makes it hard to confirm if the person is the same man as in previous videos.

A military spokesman, in a text message, said a comment would be issued in due course. The presidency declined to comment.

Boko Haram has killed about 15,000 people and displaced more than 2 million in a seven-year insurgency aimed at creating a state adhering to strict Islamic laws in the northeast of Africa’s most populous nation.