THE reported death of Boko Haram leader Abubakar Shekau last week could see large numbers of its fighters join the rival Islamic State West Africa Province (Iswap), experts warned today.

According to Nigerian intelligence officials, Mr Shekau detonated a suicide vest when Iswap militants attempted to kidnap him from his Sambisa forest base in the country’s north-east.

Iswap claim to have taken control of the Boko Haram stronghold which covers thousands of square miles and includes part of Kano state, the north-east’s commercial hub.

It would represent a major coup for the rival group, with Boko Haram having held the strategically important Sambisa forest for the past 12 years.

Details of Mr Shekau’s death remain vague and the Nigerian government has remained cautious, announcing that it was investigating and saying that no body had yet been found.

The Boko Haram leader’s death has been reported many times before, only for him to appear in video footage weeks later ridiculing such claims.

But on this occassion there has been no message from supporters denying he has been killed.

His reported demise has posed questions about the deteriorating security situation in Nigeria, with the army struggling to cope with a jihadist insurgency and the country plagued by a series of student kidnappings.

Geopolitical security analyst at the Lagos-based SMB Intelligence told Aljazeera that Mr Shekau’s death is likely to see Iswap emerge as the dominant force in the country, which would pose new challenges for the Nigerian military.

Counterterrorism expert at the University of Nigeria Freedom Onuoha said the developments would undermine the people’s confidence in the country’s armed forces to deal with the insurgency.

“That’s a major loss from a national security point of view,” he said.

Iswap has grown in recent years with the International Crisis Group estimating some 3,500 to 5,000 fighters are in its ranks compared to between 1,500 and 2,000 for Boko Haram.

Ideological differences divide the two groups with hundreds reportedly killed in sectarian fighting.

Iswap said today that new leader Abu Masab al-Banarwi had taken over all territories that had been under the control of Mr Shekau and arrested 30 top Boko Haram commanders.

The jihadist insurgency has left about 30,000 dead and displaced at least 3.2 million people across four countries in the Lake Chad basin.