Boko Haram leader Abubakar Shekau has been seriously wounded after trying to kill himself to avoid capture during clashes with rival ISIS-allied jihadists in the north of the country, two intelligence sources said.

Shekau’s Boko Haram faction and fighters from the ISIS West Africa Province had been battling in northeastern Borno state, where ISWAP militants have become the dominant force in Nigeria’s more than decade-long jihadist insurgency.

Shekau, who made international headlines when his men kidnapped nearly 300 schoolgirls in Chibok in 2014, has been reported dead several times since Boko Haram first began its insurgency in 2009.

After a series of clashes, Shekau and some of his fighters were surrounded on Wednesday by ISWAP jihadists in Boko Haram’s Sambisa forest stronghold, where they demanded he surrender, one intelligence source said.

“To avoid capture, Shekau reportedly shot himself in the chest and the bullet pierced his shoulder,”

The source also added that “He was badly injured.”

Some of his men managed to escape with him to an unknown destination, the source added.

A second intelligence source said Shekau was critically wounded after detonating explosives in the house where he was holed up with his men.

Nigeria’s army and officials did not immediately respond to requests for confirmation of the incident.

Shekau’s critical injury or death would be a blow to his Boko Haram faction which has already been weakened by military air strikes on its bases and defections among his men.

More than 40,000 people have been killed and over two million displaced from their homes by the conflict in northeast Nigeria, and fighting has spread to parts of neighbouring Chad, Cameroon and Niger.

Boko Haram and ISWAP have fought battles for control of territory in the past.

ISWAP has emerged as the stronger force, 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 the northeast into a no-go territory, 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.

Angered by Shekau’s indiscriminate targeting of civilians and use of women and children suicide bombers, a rival faction broke away in 2016 to become ISWAP with the backing of the ISIS group.