Intelligence officials in Nigeria have claimed the leader of Boko Haram is dead or seriously wounded after trying to kill himself to avoid capture during clashes with a rival extremist faction. There is no confirmation of the claims, and Nigeria’s intelligence services and military have reported Abubakar Shekau’s death many times before. But this is the first time that reports have described Shekau – who won global infamy with the kidnapping of nearly 300 female students from a college in 2014 – as dying in fighting with other militants. Nigerian intelligence officials have told reporters that Shekau and some of his fighters were surrounded on Wednesday by fighters from the Islamic State’s West Africa Province (Iswap), who attacked in dozens of pickup trucks equipped with heavy weapons. According to the officials, after killing many of his bodyguards, the Iswap fighters demanded that Shekau swear an oath of allegiance to Iswap’s leader, Abu Musab al-Barnawi. After an hour of negotiation, Shekau used either a gun, grenade or a suicide belt to attempt to take his own life, the officials said. “To avoid capture, Shekau shot himself in the chest and the bullet pierced his shoulder,” one intelligence official said, adding: “He was badly injured.” A second intelligence source claimed Shekau was critically wounded after detonating explosives in the house where he was holed up with his men. Nigeria’s army and officials in Abuja, the capital, did not immediately respond to requests for confirmation of the incident. “The groups have been sparring with more intensity and it was clear if it got to a showdown, Boko Haram have less firepower and ability,” said a local government official in Borno State, where the insurgents are strongest. “We have to wait to see if the reports [of Shekau’s death] are credible.” The offensive by Iswap began earlier this year but was paused during the Islamic holy month of Ramadan. There appears to have been little resistance this week as the group advanced into the Sambisa Forest, a vast tract of bush and woodland, and a longtime stronghold of Boko Haram. The new offensive has underlined the dominance of Iswap, which has been fighting in Nigeria for several years but has never attempted such an ambitious attack against its rivals. Analysts say Iswap and other official affiliates of Islamic State now control significant territory and populations across the Sahel region. The move into Sambisa Forest gives Iswap control over a sizeable part of the north-eastern Borno state and most of the roads into the regional capital of Maiduguri. Nigerian security forces have failed to reclaim the Sambisa Forest for the government during years of fighting. A new stronghold for Iswap there would anchor a chain of linked territories run by Isis-affiliated factions that stretches as far as the Libyan border with few breaks. Iswap is now back under the leadership of Abu Musab al-Barnawi, the son of a radical cleric whose death at the hands of security forces in 2009 was the spark the insurgency in north-east Nigeria. Boko Haram has been weakened by military airstrikes on its bases, defections and heavy losses inflicted by troops in neighbouring Chad. Early this week, the Nigerian military claimed it had killed 40 Boko Haram members in shelling in Konduga in Borno state. There was no confirmation available and the Nigerian military often make exaggerated claims. “If true, Shekau’s death will be a huge turning point,” said Bulama Bukarti, an analyst in the Extremism Policy Unit of the Tony Blair Institute for Global Change, who described Shekau as the world’s longest-lasting terrorist leader. However, Bukarti said his death would not spell the end of Boko Haram. “It will be a negative development for Boko Haram – and positive for the Lake Chad region – if the death of Shekau worsens the [Boko Haram’s] factional dispute. It will however be a positive development for the group if this leads to a reunification of the group.” Iswap has proved the more capable and disciplined force in recent years, carrying out complex attacks on the military and overrunning army bases. Shekau took over Boko Haram, formally known as the Jama’tu Ahlis Sunna Lidda’awati wal-Jihad, after its founder, Muhammad Yusuf, was killed by police in 2009. Under Shekau’s leadership, Boko Haram turned large swathes of north-east Nigeria into a no-go territory for the authorities, proclaiming a “caliphate” in the Borno town of Gwoza in 2014. An offensive since 2015 by Nigerian troops backed by soldiers from Cameroon, Chad and Niger drove jihadists from most of the area that they had once controlled. Shekau established a reputation for unpredictable violence that concerned even hardened extremists. Angered by Shekau’s indiscriminate targeting of civilians and use of women and children suicide bombers, a rival faction broke away in 2016 and with the backing of Isis formed Iswap. More than 40,000 people have been killed and more than 2 million displaced from their homes by the conflict in north-east Nigeria, and fighting has spread to parts of neighbouring Chad, Cameroon and Niger.