U.S. aid worker Jeffery Woodke has been released, according to a report Monday, after being held hostage for years in West Africa. Woodke was taken by armed men in Niger in October 2016 while working for a local NGO. His wife, Els Woodke, and a senior military official confirmed his release to The New York Times, though it’s not yet clear how Woodke’s liberation came about. “He is safe,” Els told the Times. “I don’t yet know if he is healthy.” The military official confirmed Woodke is now being medically evaluated in Niamey, the capital of Niger. In 2017, American soldiers attempted to find Doundoun Cheffou—a terrorist suspected of having played a part in Woodke’s arrest. The raid was unsuccessful and four U.S. soldiers were killed hours later in an ambush in Niger’s southwestern village of Tongo Tongo.