Fifteen soldiers were killed and a number of others wounded in an ambush on a military convoy in central Mali on Thursday, the armed forces said.
A car bomb exploded when the convoy passed, followed by heavy gunfire, the military said on Twitter.
Efforts were underway to evacuate the wounded, the statement said.
It was not yet clear who carried out the attack.
It occurred in a region where Malian, French and European forces and UN peacekeepers have been battling insurgents linked to Islamic State and Al Qaeda.
The borderlands between Mali, Niger and Burkina Faso have become ungovernable in some areas as Islamists spread.
Attacks in recent years have killed thousands of civilians and forced millions to flee.
Earlier in August, over 50 people were killed when Islamist militants raided three villages in central Mali.