Sixteen security forces were killed in an ambush in Burkina Faso's insurgent-hit north on Wednesday, three security sources said on Friday.
The attack took place near the village of Koumestenga in Namentenga province in the Center-North region, one of several areas plagued with jihadist activity.
The army did not publicly comment on the attack.
The medical charity Medecins Sans Frontieres [Doctors Without Borders] suspended its operations in an area of northwest Burkina Faso this week after armed assailants killed two of its employees.
Burkina Faso is one of several West African countries fighting a violent insurgency that took root in neighboring Mali in 2012.
Militants linked to al Qaeda and Islamic State have since spread across the Sahel and to coastal West African states despite local and foreign troops' military intervention and UN peacekeeping efforts.
The violence has killed thousands, displaced millions and contributed to growing food insecurity. It has also been a factor that has spurred two military takeovers in Mali and two in Burkina Faso since 2020.