Boko Haram has claimed a massive attack feared to be the worst in its six-year insurgency, as talks began for a regional response to the militants and fears grew of further violence.

The confirmation from Boko Haram leader Abubakar Shekau came as no surprise after multiple eyewitness accounts of the attack on Baga, which is thought to have killed hundreds, if not more.

But Shekau claimed that the Jan 3 attack, in which large parts of Baga were burned to the ground and at least 16 surrounding settlements were razed, was only a prelude to further violence.