The two deadliest clashes took place in the Centre-Nord region on Monday and early tolls spoke of dozens dead.

The army said on Friday that 33 members of auxiliary force Volunteers for the Defence of the Fatherland (VDP) died in the fighting at Noaka, in Sanmatenga province.

According to an army statement about 50 "terrorists" also died in the clash and a large amount of military materiel was recovered.

The same day a supply convoy escorted by soldiers was ambushed at Namsiguia after leaving the town of Djibo which had been besieged for months by insurgents.

"The fighting was particularly violent causing major losses," the army said, giving a provisional toll of 31 soldiers and three VDP members killed.

Reinforcements were still looking for a dozen missing men, the statement added.

A local VDP official said a third attack took place on Monday at Gayeri, in the eastern province of Komondjari, leaving four volunteers dead.

Soldiers were also ambushed in the Tia area in the west's Bolucle du Mouhoun region on Tuesday.

"During the fighting unfortunately eight soldiers suffered lethal wounds and nine more were wounded," the army said, adding that "more than 30 terrorists" had been killed.

Burkina, one of the world's poorest nations struggling with a jihadist insurgency that swept in from Mali in 2015, has since seen more than 10,000 civilians, troops and police killed, according to an NGO count.

At least two million people have been displaced.

Anger within the military at the failure to roll back the insurgency sparked two coups in Burkina Faso last year.