In pictures: Iranian nuclear plant

Iran has allowed rare access to the Bushehr nuclear reactor, where Iranian and Russian engineers have started conducting pre-conditioning tests using dummy fuel without any radioactive content.

Journalists were taken round the power plant shepherded by security guards. They included the BBC's Jon Leyne (not pictured) who called the security regime "polite but firm".

Russian and Iranian engineers are stationed at the plant which has been built and equipped by the Russian contractor Atomstroiexport.

Our correspondent says the control room looked close to completion, but in some other areas, machinery was still wrapped in plastic.

At one stage during the organised tour, Iranian atomic agency officials asked photojournalists to leave a room housing turbines.

Radar facilities dominate the skyline at the nuclear plant, which will house a 1,000-megawatt light-water reactor used for generating electricity.

The plant seems to be well defended - as in the past both Israel and the US have threatened pre-emptive military action against Iran's nuclear facilities.

Russian nuclear chief Sergei Kiriyenko attended the inauguration. Russia and international monitors will ensure the plant fulfils its job to generate energy and not to produce any weapons material.