Attack by "unidentified armed individuals" targeted "people working in a field" in the Banibangou region, close to the Mali border, says Interior Ministry.
Fifteen people have been killed in an attack in western Niger just weeks after 33 people were killed by suspected militants in the same area, the government said.
The Interior Ministry said in a statement on Wednesday that the latest attack was carried out by "unidentified armed individuals" on Monday targeting "people working in a field" in the Banibangou region, close to the Mali border.
Militancy in Sahel region
Banibangou falls inside what is known as the three-borders region between Niger, Burkina Faso and Mali, which for years has been the scene of bloody attacks by militant groups linked to al Qaeda and Daesh.
Two attacks blamed on militants at the end of July left 33 people dead, and prompted Niger to promise tougher security measures in the region and to bring the killers to justice.
The authorities have made similar promises in the past but the deadly attacks have continued, often carried out by gunmen on motorbikes who flee into Mali after their raids.
Some 1,200 Chadian soldiers are deployed in the three-borders region as part of a multinational force put together by the G5 Sahel group, which comprises Burkina Faso, Chad, Mali, Mauritania and Niger.