Boko Haram, an Islamist terrorist organization based in northeast Nigeria, has pledged allegiance to ISIS, the Islamist terrorist organization that rules a self-declared caliphate in parts of Iraq and Syria, according to an audio statement released online Saturday.

“We announce our allegiance to the Caliph … and will hear and follow him in times of hardness and success,” Boko Haram said in the statement.

The announcement confirmed a bridging between the two terror groups, as many analysts predicted would happen. ISIS has not yet responded, but is likely to accept Boko Haram’s proposal. Both groups are responsible for brutally massacring thousands of innocent civilians in the areas they operate.

Laith Alkhouri, director of Middle East research and analysis at Flashpoint Intelligence, a global security firm, told NBC News that Boko Haram is not only one of the strongest groups to support ISIS, but that it’s also active in an area where ISIS has very little, if any, control. “This gives ISIS the extra credibility and the additional territory to further its growth around the world,” Alkhouri believes.

Boko Haram has previously praised ISIS and displayed its flag in propaganda videos. Since raising its profile in 2009, Boko Haram has carried out multiple attacks, including the kidnapping of more than 270 schoolgirls in the Nigerian town of Chibok last April.

[Photo: Boko Haram video]