A senior Army officer, who refused to state if there were casualties, confirmed the incident on Friday.
According to it, many of the destroyed structures only date back to 2017, suggesting they were shelters for IDPs who came to Rann seeking protection.
The group said trouble started when the partner countries of the Multi-National Joint Task Force (MNJTF) unceremoniously withdrew from their position in the town, although no reason was given for their action.
It said the movement of the soldiers with their equipment caused panic among the civilians, mostly who were Internally Displaced People (IDP), leading to a mass exit to neighbouring Cameroon Republic.
The organisation, therefore, called on the Federal Government to investigate the withdrawal of security forces of the MNJTF from Rann, a development it said may have left tens of thousands of civilians exposed to the attack.
But speaking about the incident, the Army officer told Channels Television that the attack did occur, but the troops have since restored calm in the area.
According to him, the troops repelled the attack with the support of soldiers attached to the MNJTF Cameroon Defence Force.
The Army officer said as things were being stabilised, the MNJTF withdrew while Nigerians troops were holding on firmly on the ground and civilians who left were already returning.