Iran says 4,000 centrifuges now in operation

(CNN) - Iran's deputy foreign minister said Friday that almost 4,000 uranium-enriching centrifuges are now operating at the country's Natanz enrichment facility, the national IRNA news agency reported.

Ali-Reza Sheikh Attar told Iranian TV that another 3,000 centrifuges are being installed, IRNA said. Iran announced nearly a year ago, in September 2007, that it had more than 3,000 active centrifuges. In April, President Mahmoud Ahmadinejad promised to install 6,000 more over the coming year.

Spinning centrifuges are used to separate uranium atoms to produce uranium concentrated enough for a nuclear weapon's fission chain reaction.

The United States and other Western nations believe Iran's nuclear program is intended to develop nuclear weapons, but Iran insists it is only for peaceful purposes.