Suspected armed militants have killed 12 soldiers in Niger's remote southwest, in the latest attack since army officers seized power last month.

An operation by national guards was "the target of an ambush" on Sunday evening at the locality of Anzourou in the Tillaberi region, state television Tele Sahel reported on Tuesday.

It added that the troops' "response... led to heavy losses being inflicted on the enemy."

The troops have already been buried, in a ceremony attended by the province's military governor, Lieutenant-Colonel Maina Boucar, it said.

At least 17 soldiers were killed on August 15 near the town of Koutougou, also in Tillaberi, the authorities have said.

Twenty other soldiers were wounded while more than 100 of the assailants were "neutralised" while retreating on motorbikes, they say.

Sahel region security

The insurgents have plagued West Africa's Sahel region for more than a decade, breaking out in northern Mali in 2012 before spreading to neighbouring Niger and Burkina Faso in 2015.

But according to a toll compiled by an independent monitor, attacks in Niger fell in the first six months of this year.

In the first half of 2023, attacks on civilians fell by 49 percent compared with the same period in 2022, while the number of deaths was down by 16 percent, according to the Armed Conflict Location & Event Data (ACLED) project.