An air raid on the Mazzeh neighbourhood of the Syrian capital, Damascus, tore into a multistorey residential building and left several people killed.
The IRGC said an attack by Israeli fighter jets killed five of its “military advisers” and a number of Syrian forces.
The target of Saturday’s attack was an intelligence unit of Iran’s Islamic Revolutionary Guard Corps (IRGC), sources told.
It identified its members who were killed immediately as Hojjatollah Omidvar, Ali Aghazadeh, Hossein Mohammadi and Saied Karimi, without sharing their ranks. It later said another member, Mohammad Amin Samadi, also died after succumbing to his wounds.
Iran’s foreign ministry blamed Israel for the strike and said it “reserves the right to respond”. Israel has yet to comment.
The attack is believed to have been carried out with at least four missiles, according to Iranian state media.
Saturday’s attack comes amid widening tensions in the region and the Israeli offensive on Gaza that has killed nearly 25,000 people.