Three UN peacekeepers and one Malian solider were killed in an attack in Mali, the United Nations mission there said Friday.
The United Nations said several more people were injured, with some in critical condition.
The United Nations did not say who carried out the attack in the Menaka region, in the eastern part of Mali. Several attackers were killed when the UN unit fought back, the United Nations said.
The unit was conducting an operation to provide "medical assistance to populations in need" when the attack occurred, the United Nations said.
The members of the UN Security Council called on the Mali government to swiftly investigate the attack and bring the perpetrators to justice. The Security Council said that attacks targeting peacekeepers may constitute war crimes under international law.
Mahamat Saleh Annadif, the secretary-general for Mali and head of the UN Multidimensional Integrated Stabilization Mission in Mali, condemned the attack and saluted the bravery of the forces.
Mali has been wracked by violence in recent years, including an insurgency by Islamist and ethnic Tuareg groups that prompted French forces to intervene in the country in 2013. The United Nations established its peacekeeping mission in Mali that year.
Mali, and in particular the Timbuktu region, is one of the world's deadliest postings for UN peacekeepers.
Last August, five MINUSMA security guards, one member of the Mali National Police and one civilian contractor working for MINUSMA were killed during an attack on MINUSMA headquarters in Timbuktu.
In June, at least two tourists were killed after gunmen attacked a luxury resort popular with Westerners near Mali's capital city of Bamako.