Chefou is believed to have the led the ambush of a convoy of U.S. and Nigerien troops in October 2017 that left four American and five Nigerien soldiers dead. Formerly a Fulani herder in the Niger-Mali border region, he initially took up arms to battle Tuareg cattle thieves.[1][2] According to The New York Times, U.S. troops were attempting to locate Chefou in October 2017 when at least fifty militants purportedly led by him attacked them near the village of Tongo Tongo in southwestern Niger.[3]