All but two victims were combatants killed during five hours of fierce fighting in the Yobe state capital, Damaturu. It was the first major attack in months on an urban centre during an Islamic uprising that has terrorised northeast Nigeria.
Security forces swiftly freed major towns under the sway of the religious extremists after a state of emergency imposed in mid-May. But they have been struggling to hunt down Boko Haram militants in hideouts in local forests and caves and across borders with Cameroon, Chad and Niger, from which they emerge to attack schools and villages. Hundreds of civilians, mainly Muslims, have been killed by the militants in recent weeks, with some 40 killed in recent days.
"My brethren, this is the story I want to tell my brothers and the whole world: All this weaponry that you are seeing it is Allah who gave this to his worshippers who are fighting for Jihad all this ammunition was obtained in just one place," Shekau says.
Nigeria's military says it killed a total of 95 insurgents and lost 22 soldiers and eight police officers that day, when the insurgents set ablaze four police command posts and an army barracks.