Iran now has 5,000 working uranium enrichment centrifuges, a senior official was quoted as saying, signalling an expansion of work the West fears is aimed at making nuclear bombs.

"Now we have 5,000 running centrifuges," Gholamreza Aghazadeh, head of Iran's Atomic Energy Organisation, told the official IRNA news agency. "Suspension of nuclear enrichment is not in our vocabulary."    

Uranium enrichment can have both civilian and military purposes. Iran, the world's fourth-largest crude producer, says its nuclear programme is aimed at producing electricity so that it can export more oil and gas.

The UN nuclear agency watchdog, the International Atomic Energy Agency (IAEA), earlier this month said Iran had 3,800 centrifuges enriching uranium and that another 2,200 were being gradually introduced.

But its figures showed Iran had not boosted the number of centrifuges regularly refining uranium since reaching the 3,800 level in September. The reason for Iran's relatively slow progress was unclear, UN officials said at the time.

In a later version of the IRNA story, Aghazadeh was quoted as saying Iran had more than 5,000 working centrifuges and planned further expansion of the Natanz enrichment facility in central Iran.

Another senior Iranian official, Deputy Foreign Minister Alireza Sheikh Attar, in August said the Islamic Republic had 4,000 working centrifuges. - Reuters