Abuja, Aug 17 (IANS): Boko Haram leader Abubakar Shekau has said he is alive and still the chief of the Nigeria-based jihadist group, according to a new audio recording released on Sunday.

"The global media reported that I am dead or I am sick and have lost influence in the affairs of religion," Xinhua quoted the self-claimed Shekau as saying in the eight-minute Hausa-language recording.

"It should be understood that this is false. This is indeed a lie. If it were true, my voice would not have been heard, now that I am speaking," he said, denying previous claims by Nigerian military that Shekau had been killed.

Shekau has not appeared in recent videos from Boko Haram since March, which aroused worldwide speculation that he might have been killed or replaced by others.

Chadian President Idriss Deby said the insurgent leader who had pledged allegiance to the Islamic State (IS) was injured and replaced by Mahamound Daoud.

Boko Haram, the Nigeria-based group who sought to establish an islamic state, has been terrorising the Nigerian people and claimed responsibility for thousands of deaths since 2009.

The group stepped up its attacks since Nigerian President Muhammadu Buhari was sworn in last May, unleashing a wave of violence that has claimed 800 lives in two months.

The jihadists have recently extended their attacks into border areas of Cameroon, Chad and Niger.

Buhari tasked his military chiefs last week to end the insurgency of Boko Haram within three months.