A powerful bomb blast killed an Iranian scientist outside his north Tehran home Tuesday, a mystery-shrouded assassination that quickly triggered a round of highly charged accusations with potentially serious political repercussions.

Iran’s hard-line Islamic government blamed the U.S., Israel and other Western interests for the death of Massoud Ali-Mohammadi, 50, saying the Tehran University physicist was killed as part of an effort to slow the nation’s burgeoning nuclear research program.

Reformist websites and acquaintances, on the other hand, accused hard-liners of killing Ali-Mohammadi as a means of spreading fear on restive campuses that have become hotbeds of anti-government activity.

The charges and countercharges cast a sharp focus on Iran’s domestic and international travails and are likely to add to the nation’s volatile political atmosphere.


Iranian news outlets close to the hard-liners rushed to paint the scholar as a supporter of the government, which has forged ahead with nuclear development despite heightened international scrutiny amid allegations that Tehran is seeking to build nuclear weapons.

State television described Ali-Mohammadi as a “revolutionary university professor martyred in a terrorist operation by counterrevolutionary agents affiliated” with the West and Israel.

“I assume that this plot is the beginning of an onslaught against the country’s scientific capabilities,” Mohammed Javad Larijani, head of Iran’s Institute for Studies in Theoretical Physics and Mathematics, told the Tabnak news website. “This terrorist act revealed the criminal enemy’s plans and shows that major plots are being hatched against our country’s progress, prosperity, dignity and capability.”

President Mahmoud Ahmadinejad, whose disputed reelection victory in June was the catalyst for what have been the largest street protests since the Islamic government took power in the 1979 revolution, also blamed the West.


“Kidnapping and assassination are scenarios of a joint conspiracy against the nation of Iran,” said Ahmadinejad, according to the hard-line Fars news agency. “On the one hand, the espionage and intelligence agents of the American government kidnap a number of Iranian nationals in third-party countries and transfer them to America, and on the other hand, their treasonous agents inside Iran assassinate an intellectual citizen.”

White House spokesman Bill Burton called such allegations “absurd,” according to a transcript issued by the Obama administration. Israeli government spokesman Mark Regev declined to comment on the allegations by Iran, which contends that it is developing nuclear technology for civilian purposes only.

Colleagues and students quickly countered the official line, saying that Ali-Mohammadi was an outspoken critic of the Ahmadinejad government. As a theoretical physicist, they said, he had little applied nuclear experience.

“He was not directly involved in nuclear research,” fellow scientist Ahmad Shirzad wrote Tuesday on his blog. “Like many of us, he could give his scientific comments and remarks about nuclear research. But we cannot call him a nuclear scientist.”


Ali-Mohammadi, colleagues said, was not even employed by Iran’s Atomic Energy Organization, which oversees the country’s nuclear program.

He did serve, though, as one of two members of the Iranian delegation to the Jordan-based Synchrotron-light for Experimental Science and Applications in the Middle East, or SESAME, a United Nations-backed scientific research center building a particle accelerator with applications in molecular and medical science, according to the organization’s website. SESAME comprises nine member governments, including Israel.

Shortly after the slaying was disclosed, the Fars news agency said that a small monarchist group, the Iranian Royalist Society, had claimed responsibility on an obscure website, Takavaran-Tondar.tk. But the U.S.-based group quickly disavowed responsibility for the attack on its official website, Tondar.org.

The West and Israel have vowed to prevent Iran from obtaining nuclear weapons capability and have been trying to persuade Iranians involved in the nuclear program to defect.


Former Deputy Defense Minister Ali Reza Asgari, who allegedly procured components for Iran’s nuclear program, reportedly defected to the West in 2007. And Iran’s top diplomat last month accused the United States and Saudi Arabia of kidnapping nuclear scientist Shahram Amiri, who worked for Iran’s Atomic Energy Organization, during a summer religious pilgrimage to Saudi Arabia.

The possibility that Ali-Mohammadi was killed for political reasons could signal a new level of intrigue and possible repercussions.

Iran is in the grip of its greatest domestic crisis since the Islamic Revolution, with political violence escalating. Iran’s supreme leader Ayatollah Ali Khamenei on Saturday demanded that pro-government vigilantes rein in their activities after the assassination of opposition leader Mir-Hossein Mousavi’s nephew at a December political demonstration and a reported attack on another opposition leader, Mehdi Karroubi, last week. Some opposition leaders allege that security forces have dispatched hit squads to eliminate outspoken critics.

Shadowy groups close to Iran’s security apparatus launched a wave of high-profile assassinations against prominent dissidents during the late 1990s in an effort to terrorize a budding reform movement into silence. Some of the security officials purged after that scandal recently reemerged as proponents of the crackdown against government opponents.


On the other hand, anti-government groups based outside Iran have also engaged in bombings and other violence through the years, including attacks by suspected separatist groups along the country’s eastern and western borders.

Hard-line news outlets Tuesday described Ali-Mohammadi as a former member of the Revolutionary Guard who was a stalwart supporter of the Islamic Republic.

But the reformist news websites Ayandenews and Rahesabz said Ali-Mohammadi’s name was on a publicly available list of scholars who had campaigned for Mousavi during his unsuccessful run against Ahmadinejad.

One student wrote on an Iranian blog that Ali-Mohammadi urged his students to take to the streets in anti-government protests, even joining them in minibuses heading to demonstrations. “We must face them,” Ali-Mohammadi was quoted as saying on the blog Green Tunnel. “When you get shot, it just hurts at the beginning.”


A graduate of Tehran’s Sharif University of Technology, Ali-Mohammadi began teaching quantum physics and electromagnetic theory at Tehran University in 1995. He wrote articles on nuclear physics and advised PhD candidates on their dissertations.

Neighbors said Ali-Mohammadi had lived for decades in an old bungalow set amid new multistory apartment buildings on a quiet and leafy side street off Shariati Street in north Tehran.

Iranian news reports say he was leaving for work when the explosion occurred. Witnesses said the 7:30 a.m. blast shattered windows as far as 300 feet away. Some officials said the bomb was attached to a motorcycle. One said it was in a trash bin and set to detonate by remote control.

“Most probably, the bomb had been fixed to the motorcycle outside Mr. Ali-Mohammadi’s house and exploded by remote control,” Fakhreddin Jaarzadeh, a Tehran prosecutor, told the Iranian Students News Agency.


Photographs showed a body covered in a beige-and-maroon blanket lying next to a charred Peugeot sedan.

Two people were injured and a car was set ablaze, witnesses and news reports said.

“I was at breakfast, and our glass breakfast table shattered,” said one neighbor, who spoke on condition of anonymity.

Iranian officials said forensic experts were conducting postmortem examinations but that no suspects had been arrested.


daragahi@latimes.com

Mostaghim is a special correspondent. Times staff writer Edmund Sanders in Jerusalem contributed to this report.