Iran has condemned Israel for a missile attack that killed two members of the Revolutionary Guards near the Syrian capital Damascus on Monday.

Foreign Ministry spokesman Saeed Khatibzadeh said on Wednesday that the Israeli attack “will not go unpunished,” noting that responding to such “crimes” are the main goals of the “resistance axis” in the region.

Confirming the deaths on Tuesday evening, the IRGC vowed to avenge the death of the officers, identified as Colonel Ehsan Karbalaipur and Colonel Morteza Saeednejad. “Without a doubt the Zionist regime will pay for this crime,” the IRGC statement said.

Syrian state media had reported on Monday that an Israeli air strike on Damascus killed two civilians and left some material damage.

Iran has been deeply involved in the Syrian civil war for more than a decade, deploying tens of thousands of its own forces as well as hired Afghan, Iraqi and Pakistani Shiite fighters, who helped save Bashar al-Assad’s regime, with help from Russia.

Israel is usually silent about its attacks in Syria and Iran does not acknowledge every death. However, since 2017 Iran has been trying to set up a presence on the Israeli border possibly to create a new front to compliment what the Lebanese Hezbollah has in southern Lebanon against Israel.

Israel has mounted hundreds of such strikes against what it has described as Iranian-linked targets in Syria, hitting weapons shipments and warehouses.