A UN Humanitarian Service helicopter pilot was injured in the shooting and is in stable condition, Zhakom said of the incident that took place on Thursday.
“A detailed investigation into the incident and subsequent corrective actions have commenced regarding the very regrettable incident,” Zhakom said.
According to the UN, the deceased aid worker worked in Nigeria for the group Medecins du Monde (Doctors of the World).
The shooting shocked the humanitarian community in northeastern Nigeria, where aid workers have provided life-saving aid to millions of victims of the Islamic extremist insurgency.
The shooting prompted the UN Air Service – which transports humanitarian aid workers and supplies in the troubled region – to immediately suspend helicopter operations in the area.
The killing of the humanitarian worker is “deeply disturbing and saddening,” said Matthias Schmale, a humanitarian coordinator for the UN in Nigeria.
“All humanitarian personnel working in northeastern Nigeria deserve our full respect for their courage and commitment to stay and provide life-saving assistance to those in need in often difficult and dangerous circumstances. Humanitarian workers must be protected,” Schmale said.
Little is known about the soldier in question or his motivation for the attack, although analysts have in the past raised concerns about the mental well-being of some of the security personnel fighting in the war.
Allegations of human rights abuses committed by soldiers are also widespread, especially from locals living close to them.
“The psychological issue — the trauma and all that — might have something to do with this, but on the other hand, soldiers often behave with their guns,” said Jack Vince, a Borno-based security analyst.