The unofficial footage below released on social media shows what is reported to be one of the missiles being launched from one of Iran's western provinces.
The Revolutionary Guards are fighting in Syria against militant groups who oppose President Bashar al-Assad.
"A missile strike on militants' positions is a warning to terrorists".
Polls: Macron's brand new party to secure majority in France
He said the Socialist party needed to change its ideas and its organization and that a "collective leadership" would replace him. Foreign Minister Sigmar Gabriel also welcomed the vote's outcome, tweeting that it paved "the way for reforms in France+Europe".
The IRGC said the operation "struck them with lethal and crushing blows", adding that intelligence reports indicate "a large number of Takfiri terrorists have been killed and their equipment, systems and weapons have been destroyed".
It said the attack targeted "a command base. of the terrorists in Deir ez-Zor".
The Islamic Revolution Guards Corps also warned all Takfiri terrorists as well as their regional and ultra-regional supporters that they would receive even more devastating responses if they repeat their "satanic" moves against Iran.
Activists in Syria did not immediately have information about the Iranian-claimed strikes. ISIS claimed responsibility for the attack.
"And, of course, we need to see this in the wider geopolitical context: it will be very interesting what the reaction is going to be from countries such as Saudi Arabia, the United States and Israel, because Iran is saying it can retaliate and it will".