The west's attempts to derail Iran's nuclear program

For many years US, British, German and Israeli intelligence agencies are said to have helped to supply Iran with faulty parts designed to self-destruct and cause damage to surrounding equipment.

Over the past two years three Iranian scientists have been killed and one wounded in Tehran in what appears to be a focused campaign.

In January 2010 a particle physicist, Masoud Ali Mohammadi, was killed by a remote-controlled bomb strapped to a motorcycle as he was leaving his Tehran home on his way to work.

In November last year Majid Shahriar, of the nuclear engineering faculty at the Shahid Beheshti University in Tehran, was killed by a bomb stuck to the side of his car by an assassin on a motorbike. On the same day Fereidoun Abbasi-Davani, a nuclear physicist suspected in the west of involvement in nuclear weapons development, was injured in a similar attack. Three months later he was made head of the Iranian nuclear effort.

In July a university physicist, Darioush Rezaie, was shot dead by a gunman on a motorbike in an eastern Tehran street.

In 2010 a computer worm called Stuxnet infected operating systems at the Natanz enrichment plant, making large numbers of centrifuges crash and causing the temporary suspension of enrichment work in November that year. Enrichment restarted a few days later and Iran has made up the backlog in production, although its centrifuges have appeared to be less efficient since the Stuxnet attack.

Source: guardian.co.uk