Three United Nations peacekeepers were killed and eight others wounded in an attack in Mali’s northern city of Kidal, the UN said Friday.

The camp “came under heavy rocket/mortar fire” on Thursday and “a little later a position nearby was attacked” outside the base, the UN mission in Mali, MINUSMA, said in a statement.

The three peacekeepers were killed outside the camp. Nationalities were not given.

The attack is just the latest to target the 12,000-strong force in the west African nation. Guinean and Chadian soldiers make the majority of those at the Kidal camp.

It also came days after France circulated a UN Security Council resolution that would authorize military action by five countries in Africa’s vast Sahel region against extremist groups.

The countries are Niger, Mali, Chad, Burkina Faso and Mauritania. The joint force is expected to comprise up to 5,000 personnel, with headquarters in Mali. The European Union is providing 50 million euros in support.

MINUSMA began work in Mali in 2013, providing security and assisting Malian troops struggling to keep the country safe, but has been targeted constantly by jihadists, with dozens of peacekeepers killed.

Northern Mali fell to jihadist groups linked to al-Qaeda in March 2012, and although these forces were driven out of key towns by a French-led military intervention the following year, the extremists have now spread further south.