Gunmen attacked the headquarters of the UN peacekeeping force in the Mali city of Timbuktu, killing seven people and injuring seven others in what the mission's chief called a "terrorist" assault.
Earlier on Monday, unidentified gunmen had attacked two neighbouring UN camps in Douentza in the Mopti region of central Mali, killing a Malian soldier and a UN peacekeeper and slightly injuring another peacekeeper.
The head of the UN peacekeeping mission in Mali, Mahamat Saleh Annadif, also called that incident a terrorist attack.
UN Secretary-General Antonio Guterres condemned the attacks and warned that targeting UN peacekeepers "may constitute war crimes under international law".
He praised the "the important efforts" that Mali and four neighbouring countries are making to combat terrorism and violent extremism and promote peace in the region.
In the Timbuktu attack, the mission said five Malian security guards and a Malian contractor working for the mission were killed along with a member of the Malian gendarmerie.
It said six UN peacekeepers were wounded, two seriously, along with one Malian security guard.
The mission, known as MINUSMA, said it dispatched a quick reaction force and attack helicopters to secure the Timbuktu headquarters. It said UN troops killed six assailants.
In Douentza, MINUSMA said a group of attackers fired on a UN camp from an adjacent hill and Malian troops returned fire.
Another armed group shot at peacekeepers in a neighbouring camp who also returned fire, the mission said, and two attackers were killed in the exchanges.
The UN is looking into whether there was any connection between the two attacks.
Mr Annadif called for those responsible for "these terrorist acts" to be brought to justice.
The UN peacekeeping mission in Mali is the deadliest of its 16 global peacekeeping operations.