High-ranking Iranian nuclear physicist Mohsen Fakhrizadeh has been assassinated, the Defence Ministry confirmed on Friday.
Fakhrizadeh was shot and injured "by terrorists" in his vehicle in Ab-Sard, a suburb in eastern Tehran, and later succumbed to his injuries in what amounted to a "martyr's death," the ministry said.
Local authorities had confirmed Fakhrizadeh's death several hours earlier and also said that several attackers were killed.
Fakhrizade, 63, had been a member of Iran's Revolutionary Guard and was an expert in missile production. Fars news agency said this was why Israeli secret services had long sought to eliminate him.
Foreign Minister Javad Zarif said there was evidence pointing to the involvement of Israel in the assassination, but it was unclear who exactly conducted the hit.
Israeli Prime Minister Benjamin Netanyahu had specifically mentioned Fakhrizadeh by name in a 2018 presentation about Iran's nuclear programme.
Iran's ambassador to the United Nations in New York, Majid Takht Ravanchi, wrote in a letter to UN Secretary General Antonio Guterres and the UN Security Council on Friday that several top Iranian scientists had been killed in "terrorist attacks" over the last decade, and said "certain foreign quarters" were responsible.
He called the "cowardly" assassination of Fakhrizadeh an attempt to "wreak havoc" on the region and disrupt Iran's development in the fields of science and technology.
Nuclear weapons generation
Confirmation of the killing comes amid fresh concern about the amount of enriched uranium the country is producing. Enriched uranium is a key component for both nuclear power generation and nuclear weapons.
In 2015, a deal with world powers placed limits on the production of enriched uranium, but President Donald Trump abandoned the deal three years later, prompting Tehran to incrementally renege on its terms.
Earlier on Friday, Iranian Atomic Energy Organisation (AEOI) spokesman Behrus Kamalwandi caused confusion by denying reports of the death, saying, "our nuclear scientists are all well."
The confusion arose because Fakhrizadeh had left the AEOI and had been working at the research and technological development department of the Defence industry.
UN chief Guterres called for restraint after the killing.
"We have noted the reports that an Iranian nuclear scientist has been assassinated near Tehran today," UN spokesman Farhan Haq said on Friday.
"We urge restraint and the need to avoid any actions that could lead to an escalation of tensions in the region."