Militias have stormed a UN base in Southern Central Africa Republic (CAR), killing one peacekeeper and 21 civilians.
The UN confirmed on Wednesday that the attack happened on Monday.
Abbording to a statement from the UN, at around 5 a.m. (0400 GMT), armed anti-balaka militants attacked the base in Tagbara, about 300 km (190 miles) northeast of the capital Bangui.
The UN said ensuing gunfight lasted hours, and 22 anti-balaka were also killed.
It added that peacekeepers discovered 21 dead civilians, including four children, near a Church in Tagbara.
It was not immediately clear who was responsible for those deaths.
“Nothing can justify such acts that can be considered war crimes.
“An investigation will be conducted and will leave no room for impunity,” the UN said.
CAR was torn apart after mainly Muslim Seleka rebels ousted president Francois Bozize in 2013, provoking retaliation killings by the anti-balaka.
A 12,000-strong UN peacekeeping mission has struggled to restore order to the countryside where attacks on civilians are frequent.
The UN Security Council approved an extra 900 peacekeepers in November to help to protect civilians.
The mission has become a deadly one: more than a dozen UN peacekeepers were killed there in 2017.