In an audio message purportedly from an ISIS spokesman, the group announced that a pledge of allegiance from Nigerian-based Boko Haram has been accepted by ISIS leader Abu Bakr al-Baghdadi.
The 28-minute message, which is yet to be authenticated, was posted online by ISIS supporters.
The message says that the caliphate, or Islamic State, has expanded to western Africa and congratulated “our jihadi brothers” there.
Boko Haram’s leader, Abubakar Shekau,announced in an audio message last week that the Islamist terror group was going to ally with ISIS.
Jacob Zenn, a terror expert who lives in Nigeria, told CNN on Saturday the alliance would make sense for both groups.
“Boko Haram will get legitimacy, which will help its recruiting, funding and logistics as it expands,” Zenn said. “It will also get guidance from ISIS in media warfare and propaganda. Previously Boko Haram was a sort of outcast in the global Jihadi community. Now it is perhaps ISIS’s biggest affiliate.