Local sources said a "major" attack had killed soldiers who were hospitalised in Diffa, but they did not give figures.
An attack by Boko Haram on an army post in the southeastern Niger region of Diffa left eight dead and three missing, state radio said on Monday.
Local sources had said on Sunday that a "major" attack had killed soldiers who were hospitalised in Diffa, but they did not give figures.
Chetima Wangou came under attack by Boko Haram by around 20 heavily armed vehicles, the radio report said.
"On the friends' side there were eight dead, eight wounded, three missing. On the enemy side almost all the assailants were neutralised," the radio said.
It said there were three successive clashes and that vehicles that had managed to cross the border into Nigeria were "almost all neutralised" by air strikes by a joint multinational force of Niger, Nigeria, Chad and Cameroon.
The region which abuts Nigeria and Chad has repeatedly suffered attacks by the Boko Haram since 2015, but they have subsided since late last year.
The new attack was partially enabled by a lower water level on the Komadougou River marking the border between Niger and Nigeria, a humanitarian source told AFP.
In February last year, seven Nigerian soldiers were killed in an attack in the same village of Chetima Wangou.
Located in the Lake Chad basin in the middle of the Sahel, the Diffa region is home to 120,000 refugees from Nigeria fleeing the Boko Haram violence, as well as 110,000 people internally displaced within Niger, according to UN data released in October.