Iran’s top nuclear scientist, who American and Israeli intelligence have long charged was behind secret programs to design an atomic warhead, was shot and killed on Friday as he was traveling in a vehicle in northern Iran, Iranian state media reported.

The state media accounts said that Mr. Fakhrizadeh had been gravely wounded in the attack, and that doctors tried to save him in the hospital but could not.

No group immediately claimed responsibility for the attack.
Iranian Defence Minister Brigadier General Amir Hatami tweeted on Friday that the assassination displayed “the depth of enemies’ hatred” towards the Islamic Republic.