[1] Born in 1963,[2] Mousavi served in Syria under the IRGC's elite unit, the Quds Force, from the 1980s, facilitating the transfer of arms and funds to the Lebanese paramilitary group Hezbollah.

[3][4][5] Mousavi was killed on 25 December 2023, in a targeted Israeli airstrike at his residence in Sayyidah Zaynab, 10 km (6 mi) south of Damascus, amid the Israel–Hamas war.

[6][7] Hours after the incident, the Islamic Revolutionary Guard Corps said in a statement that, "Undoubtedly, the usurping and barbaric Zionist regime will pay for this crime.

"[5] Iranian president Ebrahim Raisi called Mousavi's killing "a sign of the Zionist regime's frustration and weakness in the region for which it will certainly pay the price".

[8] Hamas said in a statement that "the assassination of Mousavi in Syrian territory is a crime, violation of Arab sovereignty and it's a cowardly attack [which] threatens the security and stability of the entire region".