IS accepts Boko Haram pledge of allegiance

BEIRUT -- Islamic State militants have accepted a pledge of allegiance by the Nigerian-grown Boko Haram extremist group, a spokesman for the Islamic State movement said Thursday.

The development comes as both movements, which are among the most ruthless in the world, are under increasing military pressure.

Islamic State seized much of northern and western Iraq last summer giving it control of about a third of both Iraq and Syria. But it is now struggling against Iraqi forces seeking to recapture Saddam Hussein's hometown of Tikrit, while coming under fire from U.S.-led coalition air strikes in other parts of the country and in Syria.

Boko Haram, meanwhile, has been weakened by a multinational force that has dislodged it from a score of northeastern Nigerian towns.

But its new Twitter account, increasingly slick and more frequent video messages and a new media arm all were considered signs that the group is now being helped by IS propagandists.

Then on Saturday, Boko Haram leader Abubakar Shekau posted an audio recording online that pledged allegiance to IS.

On Thursday, the Islamic State group's media arm Al-Furqan, in an audio recording by spokesman Abu Mohammed al-Adnani, said Boko Haram's pledge of allegiance has been accepted, claiming the caliphate has expanded to West Africa.

Al-Adnani had urged foreign fighters from around the world to migrate and join Boko Haram.