A Borno source told said on Tuesday that the capital city was still under siege.
The insurgents were believed to belong to the Abubakar Shekau group.
“The corpses of both soldiers and civilians JTF are yet to be evacuated. We can't ascertain the numbers but certainly up to a battalion."
The attack was carried out by ISWA and killed around 100 Nigerian soldiers.
At least five soldiers were also wounded during the attack on a military camp in Kukawa village.
The post had been condemned by several Nigerians and civil society organisations.
The Nigerian military said three protesters were killed but the toll appears to have been much higher.
“The sect in massive numbers forced their way into the troops checkpoint after overrunning the Police Force"