Iran will avenge the death of Revolutionary Guards Col. Hassan Sayad Khodai, who was shot dead by two people on a motorcycle in the capital, President Ebrahim Raisi said Monday.
"I have agreed for our security forces to seriously follow up on this matter and I have no doubt that revenge for the pure blood of our martyr will be taken," Raisi said.
The semi-official ISNA news agency said members of an Israeli intelligence service network had been discovered and arrested by the Guards. The Israeli Prime Minister's Office, which oversees intelligence agency Mossad, declined to comment on the events in Tehran.
The killing on Sunday only reinforces the Guards' determination to confront the enemies of Iran and to defend Iran's security and national interests, Guards spokesperson Ramazan Sharif said, quoted by the semi-official Mehr news agency.
"The thugs and terrorist groups affiliated with global oppression and Zionism will face consequences for their actions," he said.
Israeli media said Khodai headed a unit of the Quds Force – the Revolutionary Guards' overseas arm – planning attacks on Israelis abroad.
Khodai was "one of the defenders of the shrines," the semi-official Tasnim news agency reported, referring to military personnel or advisers who Iran says fight on its behalf to protect Shi'ite sites in Iraq or Syria against groups such as Daesh.
The killing comes at a time of uncertainty over the revival of Iran's 2015 nuclear deal with world powers after months of stalled talks.
Sanam Vakil, deputy head of the Middle East and North Africa program at Chatham House, said Khodai's assassination was meant to unsettle Tehran as tensions escalate with its archenemy Israel over Iran's nuclear program.
"Should Israel be responsible for the attack, it is a reminder of Israel's growing reach and destabilising capacity inside Iran," Vakil said.
Ram Ben-Barak, a former deputy Mossad chief who now heads the Israeli Parliament's Foreign Affairs and Defence Committee, said Khodai was a familiar name.
"Yes, we know it. I don't want to get into the details of what happened or who did what. An assassination happened. Should I say I'm sorry he's no longer with us? I'm not sorry," he told public radio station Kan.
At least six Iranian scientists and academics have been killed or attacked since 2010, several of them by assailants riding motorcycles, in attacks believed to have targeted Iran’s nuclear program, which the West says is aimed at producing a bomb.
Iran denies this, saying the program has peaceful purposes, and has denounced the killings as acts of terrorism carried out by Western intelligence agencies and Mossad. Israel has declined comment on such accusations.
Iranian chief justice Gholamhossein Mohseni Ejei said Khodai's assailants would be punished.
Henry Rome of the Eurasia Group said the assassination appeared to be Israeli retaliation against the Revolutionary Guards for regional and global operations.
This approach is in line with Israel's strategy of countering Iran's actions not just in third countries but also inside Iran itself, attacking what Prime Minister Naftali Bennett calls the "head of the Octopus," Rome said.
In March, Iran attacked Iraq's northern city of Irbil with a dozen ballistic missiles in an assault on the capital of the autonomous Iraqi Kurdish region that appeared to target the United States and its allies.
Iranian state media said the Revolutionary Guards carried out the attack against Israeli "strategic centres" in Irbil, suggesting it was revenge for recent Israeli airstrikes that killed Iranian military personnel in Syria.