Boko Haram fighters attacked a military base in Mandara-Girau on Friday morning. The location sits just kilometers from Biu town in Borno State's Biu local government area.
Insurgents stormed the facility in heavy rainfall and opened fire without warning. Security sources say the attackers came in large numbers and caught troops off guard.
Nine soldiers were killed in the assault. Several others sustained injuries during the attack.
According to security officials, all the slain soldiers were beheaded. Part of the military formation fell under militant control during the fighting.
A video obtained by this newspaper shows eight soldiers' bodies covered with blankets. They lay on the ground at the overrun position.
Military authorities have not released an official statement yet. Investigations into the incident are ongoing.
