UN Secretary-General António Guterres on Tuesday called for the immediate release of the remaining hostages captured during the March 1 attack in northeast Nigeria.

On Monday Guterres condemned the killing of International Committee of the Red Cross aid worker Hauwa Mohammed Liman, one of the three nurses abducted during the March 1 attack. The attack resulted in dozens being killed, including three UN aid workers.

In November Saifura Hussaini Ahmed Khorsa was killed after approximately seven months in captivity. The last nurse, Alice Loksha, remains in captivity.

Due to the ongoing lack of basic human necessities, Guterres requests that “all parties to the conflict … protect aid workers who provide life-saving humanitarian assistance to the millions of people in need in north-east Nigeria” and that those responsible for the killings are brought to justice.