Syrian Democratic Forces fighters stand on a roof next to their flag in the village of Baghouz in Deir Ezzor province on March 24, 2019, a day they decalred victory over ISIS. AFP
Syrian Democratic Forces fighters stand on a roof next to their flag in the village of Baghouz in Deir Ezzor province on March 24, 2019, a day they decalred victory over ISIS. AFP

Mystery attacks in north-east Syria reflect challenge to SDF control