Twin blasts in Iran's capital killed a top nuclear scientist and wounded another Monday, with Tehran swiftly blaming the CIA and Mossad for the attacks apparently carried out by men on motorcycles.

Slain scientist Majid Shahriari and Fereydoon Abbasi Davani, who survived the attack, were senior figures in Iran's nuclear programme, which the West suspects of having military aims. Tehran denies the charge.

The attacks came after diplomatic cables that whistleblower website WikiLeaks released on Sunday revealed Saudi Arabia's king "repeatedly" urged Washington to take military action against Tehran's nuclear programme.

Tehran police chief Hossein Sajedi-nia said men on motorcycles attached bombs to the windows of the scientists' cars in different parts of the capital as they made their way to work. The bombs exploded seconds later.

"Dr. Shahriari was killed and his wife and driver were injured. Dr. Abbasi and his wife have been injured," he was quoted as saying in media reports.

Iranian leaders accused the US and Israeli intelligence services, the CIA and Mossad, of killing the two who were also professors at Tehran's prestigious Shahid Beheshti University.

"One can undoubtedly see the hands of Israel and Western governments in the assassination which unfortunately took place," President Mahmoud Ahmadinejad told a news conference.

Ahmadinejad's office said in an earlier statement that "the Zionist regime this time shed the blood of university professor Dr. Majid Shahriari to curb Iran's progress."

Interior Minister Mostafa Mohammad Najjar said the "Mossad and the CIA are the enemies of Iranians" whose "desperate terrorist act against the two academics shows their weakness and inferiority."

Israel's foreign ministry declined to comment on the reports.

Shahriari was "in charge of one of the great projects" at Iran's Atomic Energy Agency, the Islamic republic's nuclear chief, Ali Akbar Salehi was quoted as saying by state news agency IRNA.

He was also a member of the so-called SESAME project on nuclear cooperation in the Middle East.

The other scientist, Abbasi Davani, was targeted by UN Security Council sanctions under Resolution 1747 adopted in March 2007. He was identified as a senior defence ministry and armed forces logistics scientist.

The 52-year-old was "one of the few specialists who can separate isotopes," and has been a member of the elite Revolutionary Guards since the 1979 Islamic revolution, one report said.

"The two were cooperating with the defence ministry in the field of nuclear research. Shahriari was the head of a project that sought to achieve the technology to design nuclear reactor core," said the hardline Rajanews website.

The police chief said the assailants had managed to escape and that "nobody had yet claimed responsibility" for the attacks.

In January, Masoud Ali Mohammadi, another Iranian nuclear scientist involved with the SESAME project, was killed in a bomb attack which Tehran blamed on "mercenaries" in the pay of Israel and the United States.

Salehi warned Iran's enemies they were "playing with fire."

The latest attacks came a day after the top US military officer said the United States was weighing military options in the face of Tehran's announcement it had an atomic power plant up and running.

"We've actually been thinking about military options for a significant period of time," Admiral Mike Mullen, chairman of the US joint chiefs of staff said in an interview with CNN.

Mullen said he doesn't believe that Iran's nuclear plant is for civilian use "for a second."

"In fact, the information and intelligence that I've seen speak very specifically to the contrary. Iran is still very much on a path to be able to develop nuclear weapons, including weaponizing them, putting them on a missile and being able to use them," he said.

On Saturday, Iran said its first atomic power plant built by Russia in the southern city of Bushehr had begun operations, ahead of a new round of talks with Western powers over the country's controversial nuclear drive.

And in July, Iranian nuclear researcher Shahram Amiri said after returning to the Islamic republic that he had been held in the United States for more than a year after being "kidnapped" at gunpoint by two Farsi-speaking CIA agents in the Saudi city of Medina.