Militants at the weekend attacked a facility housing several aid groups in northeast Nigeria in what the U.N. warned on Monday is an escalation in attacks specifically targeting aid workers.
It was not immediately clear which militant group was responsible for Saturday’s attack in Ngala, near the border with Cameroon.
A more than decade-long insurgency by Islamist groups in northeast Nigeria has killed 36,000 people and left more than 7 million in need of humanitarian assistance.
Three eyewitnesses told Reuters that at least 20 displaced people awaiting assistance were killed in the attack on the facility, where aid workers live and provide assistance to displaced people.
The CNN quoted a statement from the U.N. on Monday as saying that its five staff members who were there at the time were not harmed.
“I am shocked by the violence and intensity of this attack, which is the latest of too many incidents directly targeting humanitarian actors and the assistance we provide,” U.N. Humanitarian Coordinator Edward Kallon said.