Iran's most senior nuclear scientist Mohsen Fakhrizadeh has been assassinated near the capital Tehran, the country's defence ministry has confirmed.
Fakhrizadeh died in hospital after an attack in Absard, in Damavand county.
Iran's Foreign Minister Mohammad Javad Zarif, has condemned the killing "as an act of state terror".
Western intelligence agencies view Fakhrizadeh as being behind Iran's covert nuclear weapons programme
"If Iran ever chose to weaponise (enrichment), Fakhrizadeh would be known as the father of the Iranian bomb," one Western diplomat told Reuters news agency in 2014.
News of the killing comes amid fresh concern about the increased amount of enriched uranium that Iran is producing. Enriched uranium is a vital component for both civil nuclear power generation and military nuclear weapons.
Iran insists its nuclear programme is exclusively for peaceful purposes.
Between 2010 and 2012, four Iranian nuclear scientists were assassinated and Iran has accused Israel of complicity in the killings.
Fakhrizadeh's name was specifically mentioned in Israeli PM Benjamin Netanyahu's presentation about Iran's nuclear programme in May 2018.
What happened to Mohsen Fakhrizadeh ?
In a statement on Friday, Iran's defence ministry said: "Armed terrorists targeted a vehicle carrying Mohsen Fakhrizadeh, head of the ministry's research and innovation organisation.
"After a clash between the terrorists and his bodyguards, Mr Fakhrizadeh was severely injured and rushed to hospital.
Iranian media reports said the attackers opened fire on the scientist in his car.
Fars news agency earlier reported there was a car explosion in Absard town, with witnesses reporting that "three to four individuals, who are said to have been terrorists, were killed".
What has the reaction been?
"Terrorists murdered an eminent Iranian scientist today," Iran's foreign minister said in a tweet.
"This cowardice - with serious indications of Israeli role - shows desperate warmongering of perpetrators."
Mr Zarif called on the international community to "condemn this act of state terror".
Iran's government congratulated Fakhrizadeh on his "martyrdom".
https://www.bbc.com/news/world-middle-east-55105934
