According to Iranian state and semi-state media, it was first a bombing of Mohsen Fakhrizadeh's car, which was later followed by people opening fire on the car.
Foreign Minister Javad Zarif calls those behind the act "terrorists" and writes on Twitter that there are signs that Israel has played a role in the killing.
Iran's supreme spiritual leader Ayatollah Khamenei has promised to retaliate against those responsible, writes the news agency Reuters.
The text is updated