File Photo taken on December 20, 2016, where soldiers of Burkina Faso s Armed Forces carry the coffin of servicemen killed during an attack, at the cemetery in Ouagadougou. AFP
Fourteen members of the VDP volunteer militia and four soldiers died on Monday in Sawenga in central-eastern Burkina, while five were wounded, a source said.
Another security source confirmed the toll, saying that the clash occurred during an operation to secure the area, and that "more than 50 terrorists were neutralised" in an airborne counter-attack.
Separately, a police source said a policeman and two civilians were killed on Monday night in an attack on a police border post at Yendere, on the southwestern frontier with Ivory Coast.
A trucker in the area confirmed the attack, adding that many local people had already fled into Ivory Coast because of jihadist incursions.
Ivory Coast hosts around 18,000 Burkinabe refugees, more than double the tally for 2022, according to the UN's refugee agency.
One of the poorest and most troubled countries in the world, Burkina is struggling with a jihadist insurgency that swept in from neighbouring Mali in 2015.
Nearly a third of the country lies outside the government's control, according to official estimates.
More than 10,000 civilians, troops and police have died, according to an NGO count, while at least two million people have been displaced.
Anger within the military at failures to roll back the insurgency sparked two coups last year, culminating in the ascent of a young army captain, Ibrahim Traore.
The junta has ruled out any negotiations with the jihadists.
It is staking much of its anti-jihadist strategy on the VDP, the Volunteers for the Defence of the Fatherland militia.
The force comprises civilian volunteers who are given two weeks' military training and then work alongside the army, typically carrying out surveillance, information-gathering or escort duties.
Since its inception in December 2019, the VDP has suffered hundreds of casualties, especially in ambushes or roadside bombings.
Despite the losses, the authorities launched a successful recruitment drive last year, encouraging 90,000 people to sign up, far exceeding the target of 50,000.