The militant group Boko Haram, which has wreaked Havoc in northeast Nigeria since 2009, pledged allegiance to ISIS in an apparent audio message released on Saturday.
The message, which could not immediately be verified by BuzzFeed News, was purportedly from Boko Haram leader Abubakar Shekau and addressed to the leader of ISIS, Abu Bakr al-Baghdadi.
Citing the Qu'ran's instruction to "be not divided among yourselves," the man in the recording says, "we announce our allegiance to the Caliph of the Muslims [al-Baghdadi] .. and will hear and obey in times of difficulty and prosperity in hardship and ease, and to endure being discriminated against, and not to dispute about rule with those in power," according to an English subtitles.
"We call on Muslims everywhere to pledge allegiance to the Caliph and support him," the message proclaimed.
The message was shared by Boko Haram on its social media accounts, according to the SITE Intel Group, which monitors extremist organizations.
#BokoHaram,Shekau:"We announce our allegiance to the Caliph...& will hear & obey in times of difficulty & prosperity"
The release of the message came on the same day as more than 50 people were killed in a series of blasts targeting the Nigerian city of Maiduguri.
The city has long been the focus of fighting between Nigeria's military and extremist fighters from Boko Haram, who are seeking to establish an Islamic state in the country's northeast.
The group's terrorist attacks have killed thousands of people, with the deadly fighting spreading to neighboring states.
Boko Haram made headlines last year after it kidnapped 300 girls from a Nigerian school, many of whom have still not been found.
The pledge of allegiance comes after al-Baghdadi accepted similar undertakings in November from jihadist groups in Egypt, Libya, Algeria, Yemen, and Saudi Arabia, according to the BBC.