Shugaban kungiyar Jama'atu Ahlul Sunna Lid-Da'awati wal Jihad, wadda ake kira Boko Haram, Abubakar Shekau ya ce kungiyar ce ta kai harin nan na ranar 20 ga Disamba a barikin sojojin da ke Bama a yankin arewa maso gabashin Nigeria.
