The launch was the Islamic Republic's second such missile attack on Syria in over a year.
Iranian state television and the state-run IRNA news agency said the attacks "killed and wounded" militants in Syria, without elaborating. Syrian state media did not immediately acknowledge the strike.
The TV aired footage of one of its reporters standing by as one of the missiles was launched, identifying the area as being in Iran's western province of Kermanshah. A state TV-aired graphic suggested the missiles flew over central Iraq near the city of Tikrit before landing near the city of Abu Kamal, in the far southeast of Syria.
Abu Kamal is held by forces loyal to Syria's embattled President Bashar Assad. However, the city has been targeted even now by militants from the extremist Islamic State group, who have lost almost all the territory they once held in Syria and Iraq.
One missile shown on state television bore the slogans "Death to America, Death to Israel, Death to Al Saud," referring to Saudi Arabia's ruling family. The missile also bore in Arabic the phrase "kill the friends of Satan," referring to a verse in the Quran on fighting infidels.
"In a few minutes, the world of arrogance especially America, the Zionist regime and the Al Saud will hear the sound of Iran's repeated blows."
The semi-official Fars news agency, believed to be close to the Guard, identified the six missiles used as Zolfaghar and Qiam variants, which have ranges of 750 kilometers and 800 kilometers respectively.
Iran also launched drone attacks on the site afterward, state TV reported.
The attack adds to confusion over who carried out an assault on a military parade in Ahvaz on Sept. 22 that killed at least 24 people and wounded over 60.
Iran initially blamed Arab separatists for the attack in which gunmen disguised as soldiers opened fire on the crowd and officials watching the parade from a viewing platform in the southwestern city.
Arab separatists also immediately claimed the attack and offered details about one of the attackers that ultimately turned out to be true.
The Islamic State group also claimed responsibility for the assault, but initially made factually incorrect claims about it. Later, IS released footage of several men that Iran ultimately identified as attackers, though the men in the footage never pledged allegiance to the extremist group.
In announcing the attack, Iranian state media said the missiles targeted both "takfiri" militants a term it often applies to the Islamic State group and Ahvazi separatists. The separatists have not been known to work with IS in the past.
This is the third time in the last couple of years that Iran has fired its ballistic missiles in anger.
Last year, Iran fired ballistic missiles into Syria over a bloody IS attack on Tehran targeting parliament and the shrine of Ayatollah Ruhollah Khomeini. In September, Iran fired missiles into Iraq targeting a base of an Iranian Kurdish separatist group. The separatists say that strike killed at least 11 people and wounded 50.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)