Tehran: Iran has 4,000 working nuclear centrifuges, an official said in remarks published on Friday.

Deputy Foreign Minister Alireza Shaikh Attar also told the official Islamic Republic News Agency that 3,000 more centrifuges are being installed.

Attar's statement made Iranian President Mahmoud Ahmadinejad appear to have overstated Iran's actual number of centrifuges by at least 1,000.

Ahmadinejad last month said Iran had more than 5,000 centrifuges running.

Uranium is enriched into nuclear fuel by the centrifuges to power nuclear energy plants. The same process, however, can be used to produce fuel for nuclear weapons.