Two US service members killed in ISIS-claimed attack in Syria

Two US service members were among those killed in a fiery explosion at a market in the northern Syria town of Manjib, the US military officials said.

Prior to Wednesday's attack, only two US service members had been killed in action in Syria since the start of the campaign in 2014.

Two US service members -- one Department of Defense (DoD) civilian and one contractor supporting the DoD were killed -- and three service members injured while conducting a local engagement in Manjib, the US Central Command (CENTCOM) said.

Initial reports indicate an explosion caused the casualties, and the incident is under investigation, it said.

In accordance with DoD's policy, the names of the service members are being withheld until 24 hours after notification of next of kin is complete, CENTCOM said.

"US service members were killed during an explosion while conducting a routine patrol in Syria today. We are still gathering information and will share additional details at a later time," according to a .