The attack also wounded ten people, including six peacekeepers and four members of the Malian Armed Forces.
It is unclear whether anyone has claimed responsibility for the deadly assault.
The Multidimensional Integrated Stabilization Mission in Mali posted a statement on its Facebook page from MINUSMA head, Albert Koenders, who called the attack "cowardly" and insisted that MINUSMA would continue its mission of "peace and security in Mali."
That commitment was echoed by UN Secretary-General Ban Ki-moon who said Wednesday "This attack will not diminish the resolve of the United Nations to support the Malian people in their efforts to achieve peace and stability for all of Mali." The UN head urged "all parties not to be deterred by spoilers who, through their criminal acts, seek to prevent the establishment of a sustainable peace in Mali."
The four peacekeepers who died were from Chad.