article_snippet: In the audio, which was posted online Saturday, speaker says Boko Haram's is announcing Boko Haram's "allegiance to the Caliph of the Muslims, Ibrahim ibn Awad ibn Ibrahim al-Husseini al-Qurashi," which is another name for ISIS leader Abu Bakr al-Baghdadi.
article_snippet: CNN has not been able to independently authenticate an audio message purported to be from Boko Haram's leader, Abubakar Shekau.
article_snippet: But Jacob Zenn, an expert on the terror group and is with the Jamestown Foundation, said the recording appeared to be authentic.
article_snippet: speaker said that while other messages have been faked, the speaker in this one is Shekau.
article_snippet: Zenn said the allegiance will be official when an ISIS leader such as spokesman Abu Mohammed al Adnani issues a statement.
article_snippet: Zenn said that until recently there had been little feedback from ISIS, apart from a few references to Nigerian jihadis in recent issues of the English-language Dabiq magazine.
article_snippet: It appears that a month ago ISIS set up a Twitter account on which Saturday's message was linked, Zenn said.
article_snippet: The Twitter handle was mutually promoted by Boko Haram and ISIS.
article_snippet: CNN's Steve Almasy and Evan Perez contributed to this story.
highlights_snippet: Audio message was released online Saturday and speaker is said to be Boko Haram leader .
  