Iranian President, Hassan Rouhani on Saturday accused Israel of acting as a “mercenary” for the US in carrying out the assassination of Tehran’s top nuclear scientist on Friday.

“Once again, the wicked hands of the global arrogance, with the usurper Zionist regime as the mercenary, were stained with the blood of a son of this nation,” Rouhani said in a statement on his official website, referring to the killing of Mohsen Fakhrizadeh.

Iran generally uses the term “global arrogance” to refer to the United States.

Fakhrizadeh, 59, was “seriously wounded” when attackers targeted his car before being engaged in a gunfight with his bodyguards, the defence ministry said.

Fakhrizadeh, who headed the ministry’s research and innovation organisation, was later “martyred” after medics failed to revive him.

The United States slapped sanctions on Fakhrizadeh in 2008 for “activities and transactions that contributed to the development of Iran’s nuclear programme”, and Israeli Prime Minister Benjamin Netanyahu once described him as the father of Iran’s nuclear weapons programme.

Fakhrizadeh was targeted while travelling near Absard city in Tehran province’s eastern Damavand county.

A state television reporter said a pickup truck carrying explosives concealed under a pile of wood exploded in front of his car, before it was sprayed with bullets from an SUV.

Images from the scene showed a black sedan on the side of the road, its windshield pockmarked with bullet holes. A pool of blood was seen on the asphalt.

Foreign Minister Mohammad Javad Zarif said there were “serious indications of an Israeli role” in the assassination.

“Terrorists murdered an eminent Iranian scientist today,” he tweeted.

“This cowardice — with serious indications of Israeli role — shows desperate warmongering of perpetrators.”

Zarif called on international community to “condemn this act of state terror”.

The New York Times said an American official and two other intelligence officials confirmed Israel was behind the attack, without giving further details.

A spokesman for Netanyahu questioned by AFP in Jerusalem declined to comment on the attack.

Iran’s Defence Minister Amir Hatami said Fakhrizadeh had a “significant role in defence innovations” and had been repeatedly “threatened with assassination and (was) followed.”

Speaking on television, Hatami said he “managed nuclear defence and did extensive work”, without elaborating.

He linked Fakhrizadeh’s assassination to the killing of Iran’s top general Qasem Soleimani as “completely related”.

Soleimani, who headed the Revolutionary Guards’ Quds Force, was killed in an American air strike near Baghdad airport in January.

Days later, Iran launched a volley of missiles at Iraqi bases housing US and other coalition troops, but Trump refrained from any further military response.

Iran’s armed forces chief of staff Major General Mohammad Bagheri called Fakhrizdeh’s death “a bitter and heavy blow to the country’s defence system” and warned of “severe revenge”.