The scientist Mohsen Fakhrizadeh was "seriously wounded" when assailants targeted his car before being engaged in a gunfight with his security team, Iran's defence ministry said in a statement.

It added that Fakhrizadeh, who headed the ministry's reasearch and innovation organisation, was later "martyred" after medics failed to revive him.

Fakhrizadeh, once described by Israeli Prime Minister Benjamin Netanyahu as the father of Iran's nuclear weapons programme, had been travelling in a car near Absard city in Tehran province's eastern Damavand county.

A state television report on the assassination described him as one "of our country's nuclear scientists" and said that Israel "had an old and deep enmity towards him".

Iran's Foreign Minister Mohammad Javad Zarif said there were "serious indications of an Israeli role" in the scientist's assassination.

"Terrorists murdered an eminent Iranian scientist today," Zarif wrote on Twitter.

"This cowardice -- with serious indications of Israeli role -- shows desperate warmongering of perpetrators," he added.

He also called on the international community to "end their shameful double standards & condemn this act of state terror."

Fakhrizadeh's assassination comes less than two months before Joe Biden is to take office as US president.

Biden has promised a return to diplomacy with Iran after four hawkish years under incumbent US President Donald Trump, who withdrew from the Iran nuclear deal in 2018 and began reimposing crippling sanctions.

- Series of assassinations -

Trump said at the time that the deal known formally as the Joint Comprehensive Plan of Action (JCPOA) did not offer sufficient guarantees to stop Tehran from acquiring an atomic bomb.

Iran has always denied it wants such a weapon.

Trump on Friday retweeted reports on Fakhrizadeh's assassination, without commenting on it himself.

The killing comes a day after Thailand said it had returned three Iranians jailed over a botched 2012 bomb plot in Bangkok that Israel had linked to a spate of attacks on its diplomats around the world.

Iran said the three were "a businessman and two" other Iranians detained abroad on the basis of "false accusations," without giving further information.

They killing of Fakhrizadeh is the latest in a series of assassinations of nuclear scientists in Iran in recent years that the Islamic republic has blamed Israel of carrying out.

The New York Times reported earlier in November that Al-Qaeda's second-in-command was secretly shot and killed in Tehran by two Israeli operatives on a motorcycle at Washington's behest.

The senior leader, who went by the nom de guerre Abu Muhammad al-Masri, was killed in August along with his daughter, Miriam, the widow of Osama bin Laden's son Hamza, the Times said, citing intelligence sources.

Iran said the report was based on "made-up information" and reaffirmed its denial of the presence of any of the group's members in the Islamic republic.

Iran's state news IRNA and Mehr news agency at the time reported a similar incident and identified the victims as Habib Dawoud, a 58-year-old Lebanese history teacher, and his daughter Maryam, 27, without giving further details.