Around 170 people were "executed" in attacks on three villages in northern Burkina Faso a week ago, a regional prosecutor said in a statement on Sunday.
Prosecutor Aly Benjamin Coulibaly said he received reports of the attacks on the villages of Komsilga, Nodin and Soroe in Yatenga province on 25 February, with a provisional toll of "around 170 people executed".
The attacks left others wounded and caused material damage, the prosecutor for the northern town of Ouahigouya added in a statement.
He said his office ordered an investigation and appealed to the public for information.
Survivors of the attacks told France's AFP news agency that dozens of women and young children were among the victims.
Local security sources said the attacks were separate from deadly incidents at a mosque and a church in northern Burkina Faso that also happened a week ago.
The authorities have yet to release an official death toll for those attacks.
Burkina Faso has been struggling to contain violent Islamist insurgencies linked to al Qaeda and Islamic State that have spread from neighbouring Mali over the past decade, killing thousands and displacing more than two million.
According to Acled, which gathers data on victims of conflict worldwide, the violence claimed 439 lives in January alone.
Anger over the state's inability to end the insecurity played a major role in two military coups in 2022.
Current strongman Ibrahim Traore came to power in a military coup in October 2022, vowing to win back territory from jihadists.
In February 2023, France officially ended its anti-insurgency military operations in the Sahel state, on the orders of the military junta.
(with newswires)