Two UN peacekeepers from Nigeria were killed and four others wounded in an attack Friday on a peace patrol in the town of Timbuktu in northern Mali, the United Nations said.
The UN Security Council said a member of Mali's security forces was also killed in the attack.
UN spokesman Stephane Dujarric said one of the peacekeepers killed was a woman.
UN Secretary-General Antonio Guterres and the Security Council strongly condemned the attack.
The council stressed that involvement in planning, directing, sponsoring or conducting attacks targeting UN peacekeepers may constitute war crimes.
Mali has been in turmoil since a 2012 uprising when mutinous soldiers overthrew the president. The power vacuum that resulted ultimately led to a jihadist insurgency and a French-led war that ousted the jihadists from power in 2013.
Insurgents remain active in Mali and extremist groups affiliated with al-Qaida and the Islamic State group have moved from the arid north to more populated central Mali since 2015, stoking animosity and violence between ethnic groups in the region.
Tensions have grown between Mali, its African neighbours and the West since Mali's government allowed Russian mercenaries from the Wagner Group to deploy on its territory.