In this file photo taken on July 19, 2022 Iranian President Ebrahim Raisi speaks during a joint press briefing at the Saadabad Palace, in Tehran, Iran. AP
The Islamic republic regularly calls for the destruction of the Jewish state, which in turn sees Iran, with its nuclear and ballistic missile programmes and its regional proxies, as its biggest security threat.
"Colonel Davoud Jafari, one of Iran's military advisers in Syria and a member of the Guards' aerospace arm, was killed with a makeshift bomb planted by the roadside," the Tasnim news agency reported citing a Guards statement.
The IRGC's aerospace department manufactures drones, missiles and satellites.
Tasnim said Jafari was killed on Monday "by associates of the Zionist regime" -- its term for Israel, a country with which Iran has waged a shadow war of attacks, assassinations and acts of sabotage for years.
It vowed that "undoubtedly, the criminal Zionist regime will receive the adequate response for this crime".
Tehran accuses Israel of a campaign of assassinations, including of scientists involved in what Iran insists is a peaceful nuclear programme.
The Israeli air force destroyed what it said was an Iranian drone manufacturing plant located on Syrian territory on October 24.
Syrian authorities had not yet confirmed the killing of Jafari.
Britain-based war monitoring group the Syrian Observatory for Human Rights, which relies on sources in the county, reported Jafari was killed with his Syrian bodyguard when the bomb blast hit their vehicle.
The attack took place near Sayyida Zeinab, a south Damascus district that hosts a shrine revered by shia Muslims and is home to many Iranians.
- Series of attacks -
Jafari was the highest-ranking Guards officer killed in Syria since August 23, when Tehran announced the "martyrdom death" of General Abolfazl Alijani, a Guards ground forces commander who was on a mission in Syria.
Alijani was hailed as a "defender of the sanctuary", a term used for those who work on behalf of Iran in Syria or Iraq.
Iran has long backed Syrian President Bashar al-Assad's government in the country's grinding civil war. Assad is also supported by the military wing of the Lebanese shia movement Hezbollah and by Russian forces.
Iran says it has no troops in Syria but IRGC military "advisers".
Israel has reportedly carried out multiple strikes in Syria in recent months.
They include one that killed five government troops in Damascus, and two that caused significant damage to the airport in the second city of Aleppo.
In March, the Guards announced the deaths of two high-ranking officers killed in an Israeli attack in Syria, threatening to retaliate to avenge them.
On November 9, an unclaimed raid targeted a pro-Iranian militia convoy carrying weapons and fuel from Iraq into Syria, killing at least 14 people according to the Observatory.
Israel rarely comments on its military operations in Syria.
But it has acknowledged carrying out hundreds of air and missile strikes in Syria since the civil war broke out in 2011, targeting both government positions and Iran-backed forces.