An Israeli airstrike outside the Syrian capital Damascus on Monday killed a senior adviser in Iran's Revolutionary Guards, known as Sayyed Razi Mousavi, Iranian state media reported.

Iranian President Ebrahim Raisi said the assassination of Mousavi showed weakness on the part of Israel.

"This act is a sign of the Zionist regime's frustration and weakness in the region for which it will certainly pay the price," Iranian media cited Raisi as saying.

Israel has not responded to the claim yet. 

(With input from Reuters)