beirut islamic state suicide attackers kill least 50 people triple car bomb attack thursday among group refugees northeast syria medical source kurdish red crescent say large number people also injure three car bomb set attackers source say attack take place abu fas near border deir al-zor hasaka provinces say war monitor britain-based syrian observatory human right say early least 18 people kill dead include refugees flee fight deir al-zor well members kurdish asayish security force observatory report syrian state television say dozens kill attack jihadist group lose swathe territory syria iraq year fall back towns villages euphrates valley southeast deir al-zor u.s.-backed syrian democratic force alliance kurdish arab militias press north rival offensive syrian army support ally include iran russia attack west wednesday say carry attack capital damascus three suicide bombers detonate devices near police headquarter kill two people wound six aid agencies warn fight eastern syria bad country year air strike cause hundreds civilian casualties islamic state attack kill least 50 east syria kurdish red crescent