text:  The militants ambushed troops on Monday close to Niger's border with Burkina Faso. 24 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. Late last month, 76 soldiers were killed by suspected militants in eastern Burkina Faso.