In a statement, the army said that a military ambulance struck an improvised explosive device (IED) as it was conducting an evacuation in the volatile Mopti region in central Mali.

Four soldiers were killed in the attack, it added, citing a provisional death toll.

A military source said the ambulance had been carrying an officer who had been wounded in an earlier attack near Mopti's regional capital.

Mali has been struggling to contain an Islamist insurgency that first erupted in 2012, and which has claimed thousands of military and civilian lives.

Despite the presence of thousands of French and UN troops, the conflict has engulfed the centre of the country and spread to neighbouring Burkina Faso and Niger.

Central Mali has become one of the epicentres of the Sahel-wide conflict, where ethnic killings and attacks on government forces are frequent.

On September 12, five Malian soldiers were killed in a jihadist ambush in central Mali, according to the army.

Laying roadside bombs -- or IEDs -- is a common tactic of jihadist groups in the region.