OSLO (Reuters) - Iran has been developing contacts in more than 30 countries to acquire technology, equipment and raw materials needed to build a nuclear bomb, a Norwegian newspaper said on Sunday, citing US diplomatic cables. Aftenposten said that according to the cables, obtained by WikiLeaks, more than 350 Iranian companies and organisations were involved in the pursuit of nuclear and missile technology between 2006 and 2010. Iran says its nuclear programme has purely peaceful aims but the West suspects is designed to develop a weapons capability. For years, Iran has been working systematically to acquire the parts, equipment and technology needed for developing such weapons, in violation of UN sanctions against the countrys nuclear and missile programme, Aftenposten said. Meanwhile, Iran showed its Natanz uranium enrichment plant to a group of United Nations nuclear watchdog ambassadors as a sign of transparency about its nuclear activities, state television reported Sunday. Envoys from mainly non-aligned developing nations were on the tour. Counterparts from the West, Russia and China were either not invited or rejected Irans gesture, with some saying such visits were the province of UN inspectors and could not replace talks to resolve a stand-off over Irans nuclear work. Natanz and the incomplete Arak heavy-water reactor are at the heart of a long-running international dispute over Irans nuclear program, which Tehran says has peaceful aims but the West suspects is designed to develop a weapons capability. The aim of this tour was to make it clear that America and some other countries are trying to distort the facts of Irans peaceful nuclear activities, said Ali Asghar Soltanieh, Irans ambassador to the International Atomic Energy Agency. This was an initiative to display the transparency of our activities ... and that the propaganda against our work is baseless, he was quoted by state television as saying. It was not known if the envoys were given access to Natanzs underground centrifuge production hall. Uranium hexafluoride (UF6) gas is fed into centrifuges installed at the Natanz site for enrichment of its fissile content to yield fuel for atomic power stations or, if refined to a very high degree, for nuclear warheads. Iran denies any intention to produce weapons-grade uranium, saying it wants only fuel for a future network of power plants. China and Russia, discouraged by Western officials, declined the offer. Western officials, including the EU, dismissed Irans invitation as a gambit to divide six world powers trying with a mix of negotiations and sanctions to get Iran to restrain its nuclear program and open it up to unfettered UN inspections. The next talks will be in Istanbul on January 21-22. Analysts said the selective invitation might have been aimed at fraying a new harmony among the US and European governments on the one hand, and Russia and China in their approach to Iran, on how to approach its nuclear activity. Soltanieh disagreed, saying the tour aimed at easing mistrust in Irans nuclear work. The envoys will stay in Iran until Monday. Those countries that didnt join us in this visit have lost a great opportunity, Soltanieh said. Expectations of a breakthrough at the Istanbul meeting are low after a first round of talks in Geneva last month failed to make substantial progress. Iran has repeatedly said it had no intention to halt enrichment, calling it a sovereign right. Time is on our side in the talks with the (six powers), and not on the side of the Western countries, acting Foreign Minister Ali Akbar Salehi, who is also head of Irans Atomic Energy Organization, told state television Sunday. Salehi had said Saturday that the Islamic Republics enrichment activities were progressing strongly. The world has to acknowledge our rights finally, said Salehi, the student news agency ISNA reported. Iran has been hit by four round of UN sanctions and the United States and the EU have imposed extra sanctions to push Iran to suspend sensitive uranium enrichment-related work in exchange for a packet of trade and diplomatic incentives.