The cascade of 164 centrifuges to enrich uranium is the second to be installed at the Natanz nuclear plant in central Iran, joining an already established first cascade of the same number of centrifuges.
"The new cascade at Natanz has started work in the last two weeks," Iran's deputy atomic energy organisation head Mohammad Ghannad told the Iran newspaper.
"The products of the two cascades of 164 centrifuges have been obtained and have been successfully stocked," he added, saying the uranium had been enriched to levels between 3-5 percent.
The comments, which confirm statements by an unnamed official to the ISNA agency on Friday, come amid mounting efforts by European powers and the United States to take UN sanctions action against Iran over its failure to halt enrichment.
"The results from the research in the last two weeks will complete the path of research for Islamic Republic of Iran experts and will pave the way for the industrial phase of enrichment," Ghannad said.
Iran has repeatedly made clear its intention to enrich uranium on an industrial scale that would make it self-sufficient in making nuclear fuel for its atomic programme.
"We injected gas into the new cascade and now both 164 centrifuges are working together. Passing this phase is an extraordinary and valuable experience for Iran," Ghannad said.
He told the newspaper that the International Atomic Energy Agency (IAEA) had been informed of the intended move one month ago and its inspectors visited the Natanz plant last week. Enriched uranium lies at the centre of the dispute over Iran's nuclear programme, as it can be used both to make nuclear fuel and, in highly refined form, the core of a nuclear bomb
Iran would need thousands more such centrifuges to enrich uranium on an industrial scale and its current uranium enrichment work is on a research level only.
To make a nuclear bomb, the uranium needs to be enriched to around 90 percent, far above the level needed for nuclear fuel.

Copyright AFP (Agence France-Presse), 2006