Twenty-four Malian soldiers were killed and 29 wounded in an attack on an army patrol in northern Mali on Monday in which 17 militants were also killed, a spokesman for the army said.
The West African country is still reeling from an attack on an army post that killed 54 in early November - one of the deadliest strikes against its military in recent memory, which underscored the increasing reach and sophistication of armed jihadist groups active in the wider region.
The Malian patrol attacked on Monday was in Tabankort, Gao region, while on a joint operation with Niger against militants operating near the border.
"During this attack, Malian forces suffered 24 deaths, 29 wounded as well as equipment damage. On the enemy's side, 17 were killed and a certain number captured," army spokesman Diarran Kone said.
The authorities have not named the assailants or identified which group they belonged to. From strongholds in Mali, groups with al Qaeda and Islamic State links have been able to fan out across the Sahel, destabilising parts of Niger and Burkina Faso.
Violence has surged this autumn with heavy military and civilian losses in Mali and Burkina Faso.
In addition to November's bloodshed in Mali, 38 Malian soldiers were killed on September 30 in coordinated attacks on two army bases in the centre of the country, which has slipped from government control despite the presence of the French army and other international forces.
Meanwhile, 39 people were killed in Burkina Faso on November 6 when militants attacked a convoy carrying workers of Canadian gold mining company Semafo.