Iran notched up the brinksmanship over its disputed nuclear programme Monday, abruptly postponing talks with Moscow on a plan to enrich Tehran's uranium on Russian territory to allay fears it is building an atomic weapon. Diplomats in Vienna, Austria, told the Associated Press, meanwhile, that Iran had started small-scale enrichment of uranium, a process that can produce fuel for an atomic bomb. "Uranium gas has been fed into three machines," one senior diplomat said on condition of anonymity because he was not authorised to speak on the matter. Another diplomat confirmed that limited enrichment had begun at Iran's Natanz site. State-run Iranian television later reported that Alaeddin Boroujerdi, head of the national security and foreign relations committee in parliament, said the country began its peaceful nuclear enrichment activities Monday. Boroujerdi said inspectors from the Vienna-based International Atomic Energy Agency (IAEA) were present.