There had been several attacks on senior officials in Iran in the months before Sayyad Shirazi's assassination, among them a senior judge, Ali Razini, the head of Iran's largest charity organisation, and Mohsen Rafighdoost, who were injured during separate assassination attempts.[4] According to a spokesman for Mojahedin-e Khalq, an Iranian opposition group which advocates the end of Iran's clerical regime,[2] several of the group's units had carried out the killings in northern Tehran.[3] Mojahedin-e Khalq claimed the responsibility for the assassination of Asadollah Lajevardi, a former Iranian chief prosecutor and head of Iran's Prisons Organization, who was assassinated on 23 August 1998.[1]