The death of Boko Haram commander Abubakar Shekau marked a major shift in Nigeria's grinding 12-year insurgency / © BOKO HARAM/AFP/File
Infighting between Nigeria's two major jihadist factions has left scores dead, raising the possibility of a prolonged internecine conflict between the two forces, civilian and security sources told AFP Tuesday.
Islamic State West Africa Province or ISWAP has emerged as the dominant faction in Nigeria's conflict, especially after the death of rival Boko Haram commander Abubakar Shekau in May during infighting between the groups.
His death marked a major shift in the grinding 12-year insurgency that has left 40,000 people dead, but security sources say Shekau loyalists have held out against ISWAP's bid to consolidate.
Boko Haram jihadists on Monday launched an attack on rival ISWAP militants on the Nigerian side of Lake Chad, ISWAP's bastion, seizing a strategic island, fishermen and a security source said.
Large numbers of heavily armed Boko Haram insurgents in speed boats invaded Kirta Wulgo island after dislodging ISWAP security checkpoints in an hours-long fight, those sources said.
- 'Mutually destructive fight' -
The seizure of Kirta Wulgo would be a huge setback to ISWAP as the island served as a port for importing weapons and supplies into its territory, according to security sources and local fishermen.
"It was a mutually destructive fight that lasted for more than nine hours, from 4 pm yesterday to early hours of this morning," said one fisherman in the area.
He could not give a figure for casualties, but his account was backed by two other fishermen in the region.
A local security source confirmed the clashes to AFP.
According to the security source, Boko Haram mobilised its fighters from camps in Gegime and Kwatar Mota on the Niger side of the lake and Kaiga-Kindjiria on the Chadian side.
"They gathered at Tumbun Ali island in the Nigerian side of the lake and dislodged six ISWAP checkpoints before taking over Kirta Wulgo," the security source said.
"It was a deadly fight. We are talking of more than 100 dead," the source said.
ISWAP split from Boko Haram in 2016 and rose to become the dominant jihadist group, focusing on attacking military bases and ambushing troops.
The two factions turned staunch enemies since the split and regularly fight for dominance.
Since Shekau's death in May following infighting with ISWAP militants in his Sambisa forest enclave, ISWAP has been fighting Boko Haram remnants who have refused to pay allegiance to it to consolidate its grip in the northeast.
More than two million people have been displaced by Nigeria's conflict since it began in 2009, and the violence has spread over the borders to Niger, Chad and Cameroon.
- Battles to come -
After Shekau's death, Boko Haram rebels led by Bakoura Buduma, a former Shekau lieutenant, fled Sambisa to the territory under his control in Niger's Gegime-Bosso axis of Lake Chad, according to security sources.
Last month Boko Haram suffered heavy casualties in a failed bid to invade Kirta Wulgo where they were beaten back by ISWAP, two sources in the area told AFP.
"This is just the beginning of an internecine battle between the two factions. It'll be a battle to the finish," said the local security source.
Boko Haram may want to assert their presence on the Nigerian side of the lake to get its share of fishing revenues accruing to ISWAP from levies on Nigerian fishermen.
With this sudden setback, ISWAP may look to push out the invading Boko Haram militants.
Boko Haram is now within striking distance from ISWAP's major strongholds of Sabon Tumbu, Jibillaram and Kwalleram, according to a source familiar with the area.
"ISWAP leader Abu Musab Al-Barnawi is known to reside in Sabon Tumbu where high-profile captured Boko Haram commanders are being held," the source said.
Al-Barnawi's deputy lives in Jibillaram along with other high-profile lieutenants while Sigir and Kusuma islands close to Kirta Wulgo house many of the group's senior commanders.
"All these islands are now under Boko Haram threat," the source said.
"ISWAP would use every means to ensure their safety from Boko Haram fighters who would go to any length to see they fall under their control."