Iranian nuclear scientist killed in Tehran explosion An Iranian nuclear scientist was killed Wednesday morning when a bomb ripped through his car in a northern Tehran neighborhood, Iranian media reports said. It was the fifth attack targeting an Iranian nuclear scientist in two years and will likely add to the tension between Iran and the West over the Islamic Republic's contested nuclear enrichment program. The head of Tehran's Security Council, Safarali Baratlu, blamed the attack on Israel, calling it "an act of the Zionists," according to the semi-official Fars news agency. There was no immediate response from Israel. Witnesses said a motorcyclist planted a bomb under the vehicle of the 32-year-old scientist, who was identified in media reports as Mostafa Ahmadi Roshan. "This bomb was a magnetic bomb and similar to those that they have used to assassinate scientists in the past," Baratlu was quoted as saying. At least one other person was killed in the blast, and a third person was wounded, Fars said. Roshan was a professor at Sanati Sharif University, also known as Tehran's technical university, and deputy director for commercial affairs at the Natanz uranium enrichment facility in the northern Isfahan province, Fars said. Iranian media outlets carried photos of what they said was Roshan's damaged gray Peugeot car. Other images appeared to show blood stains and car parts in the street and cleaners sweeping the area with broomsticks. Police and plainclothes security officers cordoned off a large area around the scene of the explosion, not far from Kitabi Square and the social science faculty of Allameh Tabatabai University. Passersby had their bags searched and motorcyclists were stopped and asked to present identification. Some people were body searched. Wednesday's bombing happened the day before the second anniversary of the death of Iranian physics professor Massoud Ali Mohammadi, who was killed when a booby-trapped motorbike parked near his car exploded as he was leaving his home in northern Tehran. Tehran has accused the United States, Israel and other Western interests of targeting its scientists in a bid to slow its nuclear research program, charges denied by the United States in the past. Iran's Atomic Energy Organization said the country's nuclear program would continue despite Wednesday's "heinous act." "Our path is irreversible," the organization said in a statement quoted by Iran's Arabic-language Al Alam television channel. Tension has been mounting between Iran and the West since U.N. nuclear inspectors released a report last fall asserting that Iran was conducting research that may be aimed at developing an atomic bomb. U.S. Secretary of State Hillary Rodham Clinton on Tuesday condemned Iran's decision to begin uranium enrichment at a covertly built underground facility near Qom, saying it brought Tehran "a significant step closer" to gaining the ability to produce weapons-grade nuclear material. Iran, which maintains that its nuclear program is exclusively for peaceful purposes, said this week that centrifuges in the Fordo bunker will be used to enrich uranium to 20% purity to create isotopes for medical research. About 90% purity is normally required for bomb making. Iranian officials recently threatened to close the Strait of Hormuz, a strategic channel through which 20% of the world's crude oil is shipped, if the United States and its allies continue to punish Iran with new economic sanctions.