The man believed to be the most senior figure in Iran’s nuclear program has been assassinated.

Mohsen Fakhrizadeh was ambushed by four gunmen in the town of Absard, 70km east of Tehran. He was taken to hospital but couldn’t be resuscitated.

The killing comes amid fears that Donald Trump, in collaboration with Israel and Saudi Arabia, is looking to weaken or provoke Iran before he leaves the White House on January 20.

An adviser to Iranian Supreme Leader Ayatollah Ali Khamenei promised retaliation.

‘We will strike as thunder at the killers of this oppressed martyr and will make them regret their action,’ tweeted Hossein Dehghan, a military commander.

Iranian Foreign Minister Mohammad Javad Zarif pointed suspicion in the direction of Israel, tweeting: ‘Terrorists murdered an eminent Iranian scientist today. This cowardice - with serious indications of Israeli role - shows desperate warmongering of perpetrators.’

The international community should 'end their shameful double standards and condemn this act of state terror,' he added.

In a 2018 presentation, Israel’s Prime Minister Benjamin Netanyahu named Fakhrizadeh as the director of Iran’s nuclear weapons project. After several other Iranian nuclear scientists were murdered, extra secrecy and security measures had been taken to protect him against Israeli assassins.

On Wednesday it was reported that the Israel Defense Forces were told to prepare for a potential US-ordered military strike against Iran.

Terrorists murdered an eminent Iranian scientist today. This cowardice—with serious indications of Israeli role—shows desperate warmongering of perpetrators

Iran calls on int'l community—and especially EU—to end their shameful double standards & condemn this act of state terror.

— Javad Zarif (@JZarif) November 27, 2020