U.S. troops have been involved in more firefights in West Africa than previously revealed, including a December skirmish in Niger that left 11 militants dead, the New York Times reported late Wednesday. The incidents indicate that the ambush in western Niger that killed four Green Berets in October was not an isolated incident. In fact, there were at least 10 previously unreported firefights involving American soldiers in Niger and other areas of West Africa between 2015 and 2017, the Times said. One incident on Dec. 6 involved Greet Berets and Nigerien troops who came under enemy fire and killed almost a dozen militants believed to be affiliated with the Islamic State in West Africa, the Pentagon confirmed to the Times. No U.S. troops were killed or wounded in any of the incidents aside from the October ambush. The Pentagon did not say why the firefights were not disclosed. Niger is home to a large U.S. military drone base and little is known about shadowy missions there.