This article is more than 8 years old

This article is more than 8 years old

An Iranian university professor working at one of the country's main uranium enrichment facilities has been killed in Tehran, apparently the latest victim in what is widely seen as a covert war against the Islamic republic's nuclear programme.

Attackers riding on motorcycles are reported to have attached a magnetic bomb to a Peugeot 405 carrying Mostafa Ahmadi Roshan, a 32-year-old chemistry expert from Tehran's Sharif University who held the position of a deputy director for commercial affairs at Natanz nuclear plant in central Iran.

According to the semi-official Fars news agency, Ahmadi Roshan's expertise was in making polymeric membranes for gaseous diffusion, part of the process needed for the enrichment of uranium.

Fars said Ahmadi Roshan's driver also died after being taken to Resalat hospital in Tehran. The agency said the blast took place at 8:30am local time in Shahid Golnabi street in Tehran's eastern area of Seyed Khandan.

The explosion came on the second anniversary of the killing of Masoud Ali Mohammadi, a nuclear scientist blown up outside his home by a remote-control bomb that had been attached to a motorcycle parked on the street.

Iran's nuclear programme has suffered a series of dramatic setbacks in recent years with the assassinations of its scientists in attacks similar to the one that killed Ahmadi Roshan.

In November 2010 Majid Shahriari, a nuclear scientist, was killed, and Fereidoon Abbasi Davani, Iran's current atomic chief, survived an attack by assailants on motorcycles. Last July Darioush Rezaeinejad, an Iranian academic whose affiliation to the country's nuclear activities is in doubt, was shot by gunmen riding on motorcycles.

Iranian state agencies described Wednesday's attack as a terrorist operation, and a senior official blamed Israel for it. "The bomb was a magnetic one and the same as the ones previously used for the assassination of the scientists, and is the work of the Zionists," Fars quoted Tehran's deputy governor, Safarali Baratlou, as saying. Iran refers to Israel as the Zionist regime.

Analysts believe the assassinations are related to each other and are part of a covert war aimed at disrupting Iran's nuclear programme, which Iranian authorities say is for peaceful purposes but many western governments believe has military applications.

In response to the attacks Iran has pointed the finger at Israel, the US and Britain. "Iran's enemies should know they cannot prevent Iran's progress by carrying out such terrorist acts," said Iran's vice-president, Mohammad Reza Rahimi, in quotes carried by the state Irna news agency.

Iran says western officials' public endorsement of a covert campaign against its nuclear programme is evidence of their involvement in the attacks.

On Tuesday the Israeli general Benny Gantz was quoted as telling a parliamentary panel that 2012 would be a "critical year" for Iran, in part because of "things that happen to it unnaturally".

No one has claimed responsibility for Wednesday's attack in Tehran, nor for any of the previous assassinations, but Israel has so far not denied involvement.

Iran has also referred to Israel's history of covert operations, such as Mossad's kidnapping of the nuclear whistleblower Mordechai Vanunu and the systematic killings of people involved in the Black September massacre.

Both British and US officials have also spoken of the usefulness of covert operations against the Islamic republic.

In a speech in 2010 Sir John Sawers, the head of MI6, said: "We need intelligence-led operations to make it more difficult for countries like Iran to develop nuclear weapons."

He added that the intelligence services' role was "to find out what these states are doing … and identify ways to slow down their access to vital materials and technology".

Iran has also blamed the International Atomic Energy Agency for the assassination of its scientists, accusing the UN body of revealing the names of its experts to the regime's enemies.

Iran's nuclear programme has also been hit by Stuxnet, a computer worm designed to sabotage the regime's enrichment of uranium, and its missile programme has been hit by a series of explosions.

In November 2011 an explosion at a military base killed the architect of the Islamic regime's missile programme along with dozens of its elite revolutionary guards. A similar blast last year hit a missile base in Khorramabad, Iran's nearest point to Israel.

The latest events come as fears grow of a major confrontation between Iran and the west over Tehran's nuclear programme. The west has responded to Iran's refusal to bow to international pressure by attempting to ban its oil imports; Iran has threatened to close the strait of Hormuz, a crucial passageway for oil tankers.

In defiance of the western pressure, Iran this week began uranium enrichment at Fordo facility, near the holy city of Qom, in an underground, bunker-like site built for protection against possible air strikes.