File Photo: Burkinabe soldiers patrolling near the Presidental Security Regiment (RSP) military barracks in Ouagadougou. AFP
An army unit in Solle, in Loroum province bordering Mali, came under fire at around 5am on Sunday, a source said.
"Four soldiers were killed and several were wounded... around 10 terrorists were neutralised in a counter-attack," the source said.
The armed forces swept the area with air support, the source added.
Another security source confirmed this account and said a civilian was among the casualties, although it was not known whether the individual had been killed or wounded.
The attack is the third deadly assault in two weeks against the Sahel state's beleaguered armed forces.
Its troops and police are struggling with a six-year-old jihadist insurgency that swept in from neighbouring Mali, steered by groups linked to Al-Qaeda and the so-called Islamic State.
More than 2,000 people have died and around 1.4 million have fled their homes, especially in the north and east.
On November 14, at least 57 people, including 53 police, were killed when jihadists overran a gendarmerie base at Inata, also in the north.
It was the biggest single-day loss among the security forces in the history of the insurgency.
On November 21, at least nine gendarmes and around 10 civilians were killed at Foube, likewise in the north, in an attack attributed to jihadists.
Anger at the mounting toll has spilt out into the political arena.
On Saturday, around 10 people were hurt when the security forces using teargas dispersed a rally in the capital Ouagadougou protesting at President Roch Marc Christian Kabore's security policies.