Activists in Syria did not immediately have information about the Iranian-claimed strikes.
Iran's Islamic Revolution Guards Corps has launched missiles at Daesh Takfiris' headquarters in Syria's Dayr al-Zawr, Press TV reported.
A Guard statement carried on its website said many "terrorists" were killed and their weapons had been destroyed in the strike. The Guard's website said it launched surface-to-surface medium-range missiles targeting the area. The missiles have reportedly killed large numbers of terrorists and inflicted significant material damage, Tasnim said.
On June 7, gunmen mounted nearly simultaneous assaults on Iran's Parliament and the Mausoleum of the late Founder of the Islamic Republic Imam Khomeini. Iran identifies Islamic State militants as "Takfiri terrorists".
Senior Iranian officials, however, have pointed a finger at Saudi Arabia, Iran's Sunni regional rival.
Iran has sent to Syria military advisers as well as thousands of "volunteer" fighters recruited among its own nationals as well as the Shiite communities in neighbouring Afghanistan and Pakistan since Syria's conflict broke out in March 2011.