Mohsen Fakhrizadeh, pictured in an undated photo, was head of the ministry of defence's research and innovation organisation. Reuters
Iran's president has blamed Israel for the killing of a top nuclear scientist on Friday, and said it would not slow down the country's nuclear programme.
Hassan Rouhani also said Iran would retaliate over Mohsen Fakhrizadeh's killing at a time of its choosing.
An Israeli cabinet minister said he had "no clue" who was behind the ambush by gunmen on Mr Fakhrizadeh's car.
Israel has previously accused the physicist of being key to a covert nuclear weapons programme.
Fakhrizadeh was Iran's most renowned nuclear scientist, who headed the ministry of defence's research and innovation organisation.
His killing threatens to escalate tensions over Iran's nuclear programme with the US and its close ally Israel. Read more >>