The French government has called it a terrorist attack, although no group has yet claimed responsibility.
Unidentified armed men attacked the group on August 9 in the Kouré region, about 50 kilometers from the capital Niamey.
The victims, who are French and Nigerien nationals of humanitarian organizations ACTED and IMPACT, were “murdered in a senseless and cowardly manner,” according to ACTED, which did not give further details of the incident.
French President Emmanuel Macron spoke with Nigerien President Mahamadou Issoufou about the incident that the French call “the deadly attack that cowardly targeted a group of aid workers”, according to a statement from the French presidency Monday.
“Their determination to continue the fight against terrorists in the Sahel remains intact,” the statement said.
French troops and the army in Niger and neighboring Mali are fighting to quell a jihadist insurgency, which has seen army outposts in both countries attacked by militants.
ACTED said aid workers helping vulnerable people affected by conflict should not be the target of attacks.
“This heinous crime must not go unpunished and it will not distract us from our commitment to support the Nigerien people,” the charity said in the statement.