Gunmen stormed the home of an American aid worker in Niger late Friday, killing two of his guards and whisking him away toward the Mali border, authorities said Saturday. The aid worker was reportedly kidnapped from a town called Abalak near the capital, Niamey. The mayor of Abalak told Reuters that the kidnappers “came on a motorbike and killed the guards” before “a 4x4 came and took him away and drove towards the Mali border." A spokesman for the U.S. State Department said late Friday that authorities were aware of the abduction. "The U.S. Department of State has no higher priority than the safety and security of U.S. citizens overseas," the spokesman said. No group has claimed responsibility for the kidnapping, though Islamist militants are active in neighboring Mali and have been known to abduct foreigners from Niger in the past.