An Iranian nuclear scientists was killed and another wounded in separate but identical bomb attacks in Tehran on Monday, according to local press reports.
The Fars television service said bombs were attached to both victims' cars by assassins on motorcycles, accused agents of the United States and Israel of being behind the killings.
Interior Minister Mostafa Mohammad-Najar also accused the US and Israeli intelligence
services of carrying out the assassinations.
"The CIA and Mossad have always been the enemies of Iran and constantly tried to sabotage our technological progress," he told state television.
But the minister did not present any evidence to back up the accusations.
State broadcaster ISNA further named the two victims as Majid Shahriari and Fereydoun Abbasi, both professors at Tehran's Shahid Beheshti university.
Shahriari was killed, while Abbasi and his wife were injured and hospitalized, ISNA said.
Iran's atomic chief, Ali-Akbar Salehi, told the IRNA news agency that Shahriari was a nuclear scientist and a student of his.
"I promise that we will deliver more Shahriaris to the Iranian nation, and such plots will just accelerate the speed of Iran's nuclear programmes," Salehi told Abbasi.
A pro-government website, mashreghnews.ir, said Abbasi held a PhD in nuclear physics and was a laser expert at Iran's Defense Ministry and one of few top Iranian specialists in nuclear isotope separation.
The site said Abbasi has long been a member of the Revolutionary Guard, the country's most powerful military force. It said he was also a lecturer at Imam Hossein University, affiliated to the Guard.
In January, another Iranian nuclear scientist, Professor Massoud Ali-Mohammadi was also killed.
State media said at the time that Ali-Mohammadi was killed by a remote controlled bomb strapped to a motorcycle.
Then too, Iran accused Israel and the West of the attack on a "committed and revolutionary" scientist.
But an opposition website, Jaras, said Ali Mohhamadi was an opposition supporter who backed moderate candidate Mirhossein Mousavi in a disputed election, which plunged Iran into turmoil in mid-2009.
In February 2009, the Daily Telegraph, a British, newspaper, reported that Israel was assassinating Iranian nuclear scientists as part of a covert war against the Islamic Republic's illicit weapons program.
The Telegraph quoted Western intelligence analysts as saying that Israel's Mossad spy agency was behind the death of Ardeshire Hassanpour, a top nuclear scientist at Iran's Isfahan uranium plant who died mysteriously from"gas poisoning" in 2007.
Israel and the West accuse Iran of developing nuclear weapons, a charge the Iranians deny.
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