The UNICEF communications head said a female nurse was abducted, while another female aid worker was injured in the attack.
They also said eight soldiers were killed in the attack but there was no immediate official confirmation.
A former governor of Kaduna State and ex-chairman of the National Caretaker Committee, NCC, of the Peoples Democratic Party (PDP), Senator Ahmed Makarfi has lamented the terrorist attack in Rann by suspected Boko Haram extremists.
The medical charity Medecins Sans Frontieres said on Friday it had suspended its work in the Nigerian town of Rann and evacuated national and global staff after a deadly raid.
"Right now, our thoughts are with families, friends and organisations of all those affected and the most vulnerable people aid workers strive to help in Nigeria".
Recall that NAIJ.com earlier reported that the attack happened "after dark" outside a camp housing some 55,000 people displaced by the conflict and appeared to target the military, said United Nations spokeswoman, Samantha Newport.
A United Nations spokeswoman in Abuja, Samantha Newport, said the attack happened "after dark" outside a camp housing some 55,000 people displaced by the conflict.
Guterres also announced the evacuation of all humanitarian personnel and the temporary suspension of all humanitarian deliveries in the area.
MSF teams have been providing medical care to the 40,000 people in Rann, since January 2017. "Mobile teams delivered assistance on a regular basis, and a permanent medical team has been based in Rann since September 2017", Verli said.
On Friday, Alhaji Lai Mohammed, Minister of Information and Culture said "more urgency" has been added to the search, which has expanded to neighboring countries.
This is not the first time Rann would record heavy casualties as a result of Boko Haram activities.
"We are outraged and saddened at the killings of two of our colleagues in an attack by Boko Haram in North East Nigeria last evening", he added.