8 November 2011 Updated at 19:15 ET
UN nuclear agency IAEA: Iran 'studying nuclear weapons'
Russia helped Iran build its Bushehr nuclear power plant
Iran nuclear crisis
Q&A: Nuclear issue
Iran: Heading toward a nuclear show-down?
Fuelling Bushehr
Squeezing Iran: Oil and sanctions
The UN's nuclear watchdog says it has information indicating Iran has carried out tests "relevant to the development of a nuclear explosive device".
link-
http://www.bbc.co.uk/news/world-middle-east-15643460