The African Union has condemned recurrent terrorist attacks targeting civilians in Niger.
At least 137 Nigerien civilians were killed on Sunday in an attack on several localities near the Malian border.
It was the second deadly attack on Nigerien civilians in a week.
On March 15, unidentified gunmen attacked and killed at least 58 civilians returning from a weekly market in the Banibangou department, Tillaberi region, near the Malian border.
In a Statement issued on Tuesday, AU Commission Chair Moussa Faki Mahamat expressed his outrage and concern at the attacks.
He also reiterated the urgent need to strengthen the fight against terrorism in the Sahel to preserve human lives.
Following the attack, the Nigerien government announced a three-day national mourning to pay tribute to the victims.
Niger, Burkina Faso, and Mali in the Sahel are at the epicenter of one of the world's fastest-growing displacement and protection crises.
The region hosts Eight hundred and fifty-one thousand refugees and nearly two million displaced people, according to the UN Refugee Agency.