text:  The militants ambushed troops on Monday close to Niger's border with Burkina Faso. Twenty-four soldiers are still reported missing. The attack comes just two days after the junta leaders of Burkina Faso, Mali and Niger formalized their alliance and declared a confederation of Sahel states. The region has seen increased attacks in recent weeks. The violence has raised questions about the capacity of the army and their Russian allies to contain the insurgents' attacks.