One hundred people were killed on Saturday in attacks on two villages in western Niger, says Prime Minister Brigi Rafini.
Rafini announced the death toll in remarks broadcast on national television on Sunday from a visit to the zone, near the border with Mali. He did not say who was responsible for the attacks.
Security sources said on Saturday that at least 70 civilians had been killed in simultaneous attacks by suspected Islamist militants on the villages of Tchombangou and Zaroumdareye.
Niger has suffered repeated attacks by militants linked to al Qaeda and Islamic State near its borders with Mali and Burkina Faso. The violence is part of a wider security crisis in West Africa's Sahel region that has unnerved Western allies like France, who have poured troops and resources into the region.
It has also seen tit-for-tat killings between rival ethnic communities that have been stoked by violence and competition for scarce resources.
Saturday's attacks came on the same day that the electoral commission announced the results from the first round of the election to replace President Mahamadou Issoufou, who is stepping down after a decade in power.
Ruling party candidate Mohamed Bazoum, who finished in first, expressed his condolences on Sunday to the victims.
The attacks, he said in a video he posted on social media, "remind us that terrorist groups constitute a grave threat to cohesion within communities unlike any other".
Bazoum will face former President Mahamane Ousmane in a second round run-off expected on 21 February.
-Reuters