An Iranian scientist with nuclear links has been shot dead outside his house in Tehran after being targeted by attackers on a motorcycle.

Local reports say that the man, Daryoush Rezaei, was a physicist at a university in Tehran. He was also a nuclear expert with links to the Atomic Energy Organisation of Iran.

In 2010, another nuclear scientist, Massoud Ali Mohammadi, was killed by a remote-controlled bomb in the capital. That attack was blamed on Israeli secret service Mossad.

Iran announced last week that it was installing more advanced centrifuges in a uranium enrichment plant as part of its acceleration of the country’s nuclear programme. The installation will triple the rate at which it enriches uranium.

Western countries said the announcement undermined Tehran’s claim that its nuclear programme is for purely peaceful purposes.