An Israeli attack in Syria on Friday killed an officer in Iran's Revolutionary Guards, the Guards said, as the second strike near Damascus in two days pointed to an intensifying Israeli effort to counter Tehran's foothold in the country.
There was no immediate statement from Israel, which usually declines to comment on reports of strikes in Syria.
"The Revolutionary Guards Corps (IRGC) has announced the martyrdom of guardsman Milad Haydari, one of the IRGC's military advisers and officers", in the Israeli attack, the IRGC said in a statement reported by Iranian media.
The Guards vowed to respond, saying the "criminal attack" on the outskirts of Damascus at dawn would not go "unanswered", the semi-official Iranian news outlet Tasnim reported.
The air strike was the sixth attack by Israel in Syria this month, according to the Syrian Observatory for Human Rights.
Israel has for years been carrying out attacks against what it has described as Iran-linked targets in Syria, where Tehran's influence has grown since it began supporting President Bashar al-Assad in the war that began in 2011.
Iran says its officers serve in an advisory role in Syria at the invitation of the Damascus government. Dozens of IRGC members including senior officers have been killed in Syria during the war.
Citing a military source, Syrian state media reported that Israel had fired "sprays of missiles" just after midnight that hit "a site in the Damascus countryside," without specifying further.
"Syrian air defenses intercepted the missiles and shot down a number of them," the source said, saying the attack caused some material damage. There were no details about casualties.
Iranian-backed groups, including Lebanon's Hezbollah, and Iraqi paramilitary groups have positions around the capital and in Syria's north, east and south.
The new attack follows a strike overnight on Thursday that left two soldiers wounded, according to Syrian state media.
Intensifying Israeli strikes
A source with Syria's opposition factions said the strike on Thursday hit a car carrying pro-Iran personnel near a Syrian security building.
Iran "strongly condemned the Thursday and Friday morning attacks of the aggressor Zionist regime on some centers in Damascus and its suburbs," foreign ministry spokesperson Nasser Kanaani said in an online statement on Friday.
Friday's overnight attack caps a month of particularly intense air strikes on Syria, with at least six in March alone, according to a tally by the Syrian Observatory, a UK-based war monitor with sources in the country.
On March 22, an Israeli strike near the northern city of Aleppo's airport put it briefly out of service. Regional intelligence sources said the attack hit an Iranian arms depot.
Iran-backed groups then launched armed drones at a base hosting US forces in the northeast, killing one American contractor and wounding another, as well as several troops.
The US responded with air strikes on installations in eastern Syria that it said were affiliated with the IRGC.
The US said on Thursday six US troops suffered traumatic brain injuries during the tit-for-tat exchanges last week.
