On Sunday Iran vowed severe revenge against Israel not only for the killing of Hezbollah chief Hassan Nasrallah during massive bombings on Friday in Beirut's southern suburbs, but for the death of a top Revolutionary Guard official in the same airstrikes.

Iran's Foreign Minister Abbas Araghchi gave high level confirmation for the first time that IRGC Deputy Commander, Gen. Abbas Nilforoushan - who apparently was meeting with Nasrallah at the time - was killed.

Araghchi warned that this "horrible crime of the aggressor Zionist regime" will "not go unanswered." However, he stopped short of specifying whether it would be a military response.