Seventeen troops died in an insurgent ambush in Niger, the government said, in a reminder of the nation's deep security crisis as its military rulers face off against neighbours determined to reverse last month's coup.
An army detachment was "the victim of a terrorist ambush near the town of Koutougou" in the Tillaberi region near Burkina Faso on Tuesday, a defence ministry statement said.
It added that another 20 soldiers had been wounded, six seriously, with all the casualties evacuated to the capital Niamey.
More than 100 assailants, who were travelling on motorbikes, were "neutralised" during their retreat, the army said.
The insurgency has plagued 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.
The so-called "three borders" area between the three countries is regularly the scene of attacks by rebels affiliated with the Daesh terrorist group and Al Qaeda.
The unrest across the region has killed thousands of troops, police officers and civilians and forced millions to flee their homes.
Anger at the bloodshed has fuelled military coups in all three countries since 2020, with Niger the latest to fall when its elected president, Mohamed Bazoum, was ousted on July 26.
Alarmed by the cascade of takeovers, the West African bloc ECOWAS has warned of possible military intervention to reinstall Bazoum, who is being detained in the presidential compound in Niamey.
Military chiefs of the Economic Community of West African States (ECOWAS) are to meet in Ghana on Thursday and Friday to follow through a decision by their leaders last week to deploy a "standby force to restore constitution al order" in Niger.
Analysts say an intervention would be militarily and politically risky, and the bloc has declared that it prefers a diplomatic outcome.
Bazoum's election in 2021 was a landmark in Niger's history, ushering in the country's first peaceful transfer of power since independence from France in 1960.
He survived two attempted coups before being toppled in the country's fifth military takeover.
Niger is also facing an insurgency in its southeast from militants crossing from northeastern Nigeria -- the cradle of a campaign initiated by Boko Haram in 2010.