The soldiers - who were from Togo - were travelling in the Mopti region when their vehicle came under fire before hitting a landmine.
The area is known as a stronghold for the Macina Liberation Front, a jihadist group with suspected al-Qaeda links.
According to a press statement from the UN Multidimensional Integrated Stabilization Mission in Mali (MINUSMA), the ambush occurred at about 11:00 a.m. near the town of Sevaré.
In the wake of the deadly ambush, Secretary-General Ban Ki-moon and the UN Security Council also condemned the incident, with the UN chief calling for swift action to bring the perpetrators of this crime to justice.
“Mr. Ban observes with sadness that this latest attack on MINUSMA has taken place on the International Day of UN Peacekeepers, when the men and women serving under the United Nations flag with honour, courage and dedication are to be honoured,” said a statement issued by his spokesperson, referring to the annual 29 May commemoration, declared by the UN General Assembly in 2003.
The UN mission was set up in 2013 to stabilise Mali following a rebellion by Islamist and Tuareg fighters. Militants have been mounting sporadic assaults on peacekeepers in northern and central regions.
The statement also underscored that the Secretary-General recalled, once again, that attacks targeting peacekeepers may constitute war crimes under international law.
For its part, the Security Council, in a press statement, reaffirmed that all forms and manifestations of terrorism represent a serious threats to international peace and security. The Council also expressed concern about the security situation in Mali.
Council members noted that the full implementation of the Agreement for Peace and Reconciliation in Mali and the intensification of efforts to overcome asymmetric threats can contribute to improving the security situation across the entire country. They further stressed the importance that MINUSMA has the necessary capacities to fully fulfil its current mandate.
Through their respective statements, MINUSMA, the Secretary-General and the members of the Council all expressed condolences to the families of victims, as well as to the Government and people of Togo, and wished a speedy recovery to the injured peacekeeper.