Two U.S. service members, one Department of Defense civilian and one contractor were killed by an explosion while conducting a local engagement in the northern Syrian town of Manbij on Wednesday.
Three other U.S. service members were injured in the blast, according to U.S. officials.
Operation Inherent Resolve, the U.S.-led mission to defeat the Islamic State, did not provide further information regarding the cause of the explosion.
ISIS claimed responsibility for the attack through the group’s propaganda arm. The terror group said one of its members conducted the attack in Manbij using a suicide vest filled with explosive material.
Video of the attack was reportedly recorded by CCTV footage, showing a busy street with civilians passing a store front just before a blast erupts from a building.