An adviser to Iran's supreme leader warned Sunday that Israeli embassies are "no longer safe" after a strike in Syria which Tehran blamed on Israel killed seven Revolutionary Guards members.

"The embassies of the Zionist regime are no longer safe," Yahya Rahim Safavi, senior adviser to Ayatollah Ali Khamenei, was quoted as saying by the ISNA news agency.

Tehran has vowed to avenge Monday's air strike on Damascus that levelled the Iranian embassy's consular annex, killing seven Islamic Revolutionary Guard Corps (IRGC) members including two generals.

"The resistance front is ready; how it (the response) will be, we have to wait," Safavi said, noting that "confronting this brutal regime is a legal and legitimate right".

He also noted that multiple Israeli embassies around the region "have been shuttered".

There was no immediate comment from Israel.

Monday's attack, which Britain-based war monitor the Syrian Observatory for Human Rights said killed 16 people, was the fifth raid on Syria in a week blamed on Israel.

Among the dead were generals Mohammad Reza Zahedi and Mohammad Hadi Haji Rahimi who were senior commanders in the Quds Force, the IRGC's foreign operations arm.

Zahedi, 63, had held several commands during a career spanning more than 40 years.

He was the most senior Iranian soldier killed since a United States missile strike at Baghdad airport in 2020 killed Quds Force chief General Qasem Soleimani.

Monday's strike in Damascus took place against the backdrop of the Gaza war which began with Hamas's October 7 attack on Israel which killed 1,170 people, mostly civilians.

Tehran backs Hamas but has denied any direct involvement in the attack which sparked massive Israeli retaliation against the Gaza Strip.

The Hamas-run health ministry in the Palestinian territory says at least 33,175 people have been killed there during six months of war.

Iran does not recognise Israel, and the two countries have fought a shadow war for years.

The Islamic republic accuses Israel of having carried out a wave of sabotage attacks and assassinations targeting its nuclear programme.