Nearly 200 fighters have been killed in violent clashes between Boko Haram and the Islamic State West Africa Province (ISWAP) in northeastern Nigeria, sources told AFP on Monday.

The fighting broke out on Sunday in the Dugon Chiku area near Lake Chad, according to Babakura Kolo, a leader in a pro-government militia assisting the Nigerian army. “From the figures we gathered, around 200 ISWAP militants were killed in the confrontations,” he said.

A former Boko Haram member who has since renounced violence but continues to monitor armed group activities in the region, also reported that roughly 300 ISWAP fighters were killed and “a significant amount of weapons were seized.”

The Lake Chad basin has for years been the scene of fierce rivalry between the two extremist factions, each seeking control over territory, fighters and resources.