Iranian supreme leader Ayatollah Ali Khamenei calls for 'punishing' those who were behing Scientist Mohsen Fakhrizadeh's killing. Fakhrizadeh was a top nuclear scientist in Iran and was assassinated on Friday. Khamenei added that Scientist Fakhrizadeh's work must be taken forward. His statement was published on his official website. Khamenei called for "following up on this crime and certainly punishing the perpetrators and those responsible, and ... continuing the scientific and technical efforts of this martyr in all of the fields he was working in," Khamenei called the scientist a "prestigious nuclear and defence scientist" and said he was "martyred by the hands of criminal and cruel mercenaries"."This unparallelled scientist gave his dear and valuable life to God because of his great and lasting scientific efforts, and the high prize of martyrdom is his divine reward," he added. The ministry said that the scientist, who headed its research and innovation organisation, died after medics failed to revive him during the treatment. Iran's President Hassan Rouhani had vowed that Iran will not "leave this criminal act unanswered" and will retaliate "in due time." About the killing, the President informed, "The nation of Iran is smarter than to fall in the trap of the conspiracy set by the Zionists. They are thinking of creating chaos, but they should know that we have read their hands and they will not succeed". Iran sees 'arch-enemy' Israel in killing of prominent Iranian nuclear scientist US sanctions Russian and Chinese companies for supporting Iranian missile program Observatory said airstrike kills 19 Iran-backed militias in Syria