In the lake chad region, rival groups Boko Haram and one of ISIS's splinter groups, the Islamic State’s West Africa Province, share large swathes of territory.
But the rivalry between the groups is mounting and ISWAP appears to have gained extensive control over the region.
Two weeks ago, the ISIS branch launched an operation on Boko Haram lands, in the Sambisa forest.
Fighters surrounded the house of their leader Abubakar Shekau.
Nigerian intelligence officials claimed he is either dead or seriously wounded after trying to kill himself to avoid capture.
Neither of the jihadist groups has announced his death.
ISWAP executed at least ten Boko Haram commanders, while thirty other prominent members of the organiSation joined it, according to sources-
It now means ISWAP now has more territory, fighters and weapons.
Unlike Boko Haram who kill civilians, ISWAP prefers to gain their trust and collect their money- which they say is a security tax.
The fighters told residents they wanted to "put an end to Boko Haram, and then turn to Nigerian soldiers,"
As usual, the group has embarked on "a campaign of seduction among civilians in its old and new areas of influence," said on Twitter Vincent Foucher, a researcher at the French Center for Scientific Research (CNRS), citing sources in the region.
"Iswap fighters would claim that Shekau is dead, that they now control the area, and that Muslim civilians are safe as long as they pay Islamic tax," Vincent Foucher continues in his Tweet.
In addition to the Sambisa forest, the Boko Haram group has important strongholds on both sides of the border with Cameroon at Gwoza, Pulka, and in the mountains of Mandara, as well as in Niger.