TEHRAN - A remote-controlled bomb killed a Tehran University nuclear scientist Tuesday, state media reported, in an attack which Iran blamed on its two arch enemies, the United States and Israel.
The blast which killed professor Massoud Ali-Mohammadi occurred at a time of heightened tension in the Islamic Republic, seven months after a disputed presidential election plunged the major oil producer into turmoil.
It also coincided with a sensitive time in Iran's row with the West over its nuclear ambitions, with major powers expected to meet in New York Saturday to discuss possible new sanctions on Tehran over its refusal to halt its atomic work.
Such bombing attacks are rare in the Iranian capital. In October, a suicide bomber killed dozens of people in Iran's southeast, including senior Revolutionary Guards officers.
State broadcaster IRIB described Ali-Mohammadi as a committed and revolutionary professor, suggesting he backed the government of hardline President Mahmoud Ahmadinejad.
The semi-official Fars News Agency quoted one of his students as saying he had worked with the elite Revolutionary Guards until 2003. It quoted a pro-government milita, Basij, as saying he had also been at two Guards-affiliated universities.
But an opposition website, Jaras, said he was an opposition supporter whose name was among hundreds of other academics who issued a statement in favor of moderate candidate Mirhossein Mousavi during the campaign for last June's election.
Officials blamed Israel and the United States for the bombing. Signs of the triangle of wickedness by the Zionist regime (Israel), America and their hired agents, are visible in the terrorist act, the Foreign Ministry said.
Such terrorist acts and the apparent elimination of the country's nuclear scientists will definitely not obstruct scientific and technological processes, it added.
Western capitals suspect that Iran's nuclear program is aimed at developing bombs. Tehran denies this, saying it only seeks to generate electricity.
A spokesman for Iran's Atomic Energy Organization, Ali Shirzadian, said Ali-Mohammadi was not working for the organization, Fars reported. Tehran University's website showed his recent research papers were on the nature of dark energy, a highly theoretical area of cosmology.
Mark Fitzpatrick, chief proliferation analyst at London's International Institute for Strategic Studies, said Israel had in the past killed people working on nuclear programs it perceives as hostile.
But he said it was unlikely Tuesday's attack was part of an Israeli or American strategy to deprive Iran of the brains of the (nuclear) enrichment process. There are by now too many scientists and engineers with the requisite expertise.
The bombing follows the disappearance in June of Shahram Amiri, a university researcher working for the Atomic Energy Organization, during a pilgrimage to Mecca.
Amiri vanished three months before Iran disclosed the existence of its second uranium enrichment site, near the city of Qom. In December Tehran accused Saudi Arabia of handing Amiri over to the United States.
Fars quoted a foreign-based group, the Iran Monarchy Association, as claiming responsibility for Tuesday's bombing. It did not say how it obtained the statement.
Iranian universities have been the scene of rival protests by opposition campaigners and government supporters since the June poll, which the reformist opposition says was rigged to secure Ahmadinejad's re-election.
Student activists form the backbone of the reform movement.
English-language Press TV said Ali-Mohammadi, a 50-year old lecturer of neutron physics, was killed Tuesday morning in a northern part of the capital by a booby-trapped motorcycle as he was leaving his home.
It showed footage of broken glass and other debris at the scene, with what appeared to be the dead man in a body bag taken away on a stretcher. Another media report said windows were shattered within a distance of 50 meters from the blast.
Everyone I know is blaming the United States and Israel for this crime, said Tehran University professor Mohammad Marandi.
Iran has been convulsed by its most serious domestic unrest since the Islamic revolution in 1979, as protests by opposition supporters against the election result have turned violent. Authorities deny opposition allegations that voting was rigged.
Eight people were killed in clashes between security forces and opposition supporters on Ashura, the day of ritual Shi'ite Muslim mourning that fell on December 27.
(Additional reporting by Mark Heinrich in Vienna; Editing by Dominic Evans)