At least four police officers from Niger were killed in what a security source described Monday as a "terrorist" attack near the west African nation's border with Mali and Burkina Faso.
The attack on Sunday struck Wanzarbe, a town located in the western region of Tillaberi -- one of a string of areas where Niger declared a state of emergency Saturday.
"The provisional toll is four police officers killed in a clear terrorist attack on Sunday night," the security source said.
The assault targeted a police station, he added.
Tillaberi and neighbouring region Tahoua have witnessed several deadly attacks on army posts and refugee camps, blamed by authorities on Malian jihadists linked to the Movement for Oneness and Jihad in West Africa (MUJAO) group.
These include a late February attack in Ouallam, Tillaberi which killed 16 soldiers and wounded 18. And in October, 22 soldiers died in Tahoua during a daring assault on a refugee camp.
At least 43 soldiers were killed in jihadist attacks from October 2016 to February this year in Tillaberi and Tahoua.
Niger shares its southern border with Nigeria which has been struggling with a bloody seven-year uprising by the Boko Haram extremist group that has so far claimed more than 20,000 lives.
The insurgency began in northeast Nigeria but has since spread to Chad, Cameroon and Niger.