"Two vehicles from the Malian armed forces were blown up by an improvised explosive device causing the death of five Malian soldiers and wounding four others yesterday," an army statement said.
The government pledged in the statement that "everything will be done to locate and bring those responsible to justice" for the attack between the localities of Ansongo and Indelimane.
Mali's vast, desolate north fell under the control of the Tuareg-led rebels who allied with jihadist groups linked to Al-Qaeda in 2012.
However, rival armed factions and smuggling networks mean the region has struggled for stability since the west African nation gained independence in 1960.