On 18 June , the Syrian Army reportedly cut the road between ISIL-held towns of Al-Qaim to Al-Sukhnah , entered Deir ez-Zor Governorate from the south , while capturing large parts of the Syrian Desert from ISIL . Meanwhile , IRGC Aerospace Force bases in west Iran fired six surface-to-surface mid-range missiles targeting ISIL forces in the Deir ez-Zor Governorate . It was officially announced as a response to the terrorist attacks in Tehran earlier that month
terrorist attacks in Tehran
2017 Tehran attacks
Syrian Desert campaign (May–July 2017)