Militants killed 17 Malian soldiers and four civilians in an attack near the town of Tessit on Sunday, the Malian army said.
Nine soldiers were also reported missing and vehicles and equipment were destroyed, it said in a statement released late on Monday, adding that it suspected an Islamic State affiliate.
"On 07 August 2022 around 15h00, the army units of Tessit... responded vigorously to a complex and coordinated attack by armed terrorist groups, presumably from ISGS (Islamic State in the Greater Sahara) and benefiting from drone and artillery support," the statement said.
Mali is facing a worsening insurgency by Islamist armed groups, some linked to al-Qaeda and Islamic State, which has expanded to its neighbours Burkina Faso and Niger.
The army said it killed at least seven on the enemy side.