A team of UN inspectors arrived today in Iran to visit a recently revealed, though still unfinished, uranium enrichment facility near the holy city of Qom to verify it is for peaceful purposes.

The revelation last month by Iran of the facility's existence, known as Fordo, raised international suspicion over the extent and aim of Tehran's nuclear programme.

But Iran says that by reporting the existence of the site voluntarily to the UN's nuclear watchdog, it "pre-empted a conspiracy" against Tehran by the US and its allies who were hoping to present the site as evidence that Iran was developing its nuclear programme in secret.

Iran insists its nuclear programme serves to generate power and denies allegations it is trying to make nuclear weapons.

The delegation from the International Atomic Energy Agency is led by Herman Nackaerts, director of IAEA's Division Of Operations Department Of Safeguards. The inspectors are expected to stay three days in Iran.

The Fordo uranium enrichment site, Iran's second, is said to be in the arid mountains near the holy city of Qom, inside a heavily guarded, underground facility. It is located about 30 km north of Qom.

Iran says the facility will not be operational for another 18 months. The small-scale site is meant to house no more than 3,000 centrifuges, much less than the estimated 8,000 machines at Natanz, Iran's known industrial-scale enrichment facility.