"They arrived in the middle of the night," IAEA spokeswoman Melissa Fleming told AFP from the UN watchdog's headquarters in Vienna, adding that the inspectors would remain in Iran for "several days."

The visit comes after Tehran, under pressure to prove that it is not trying to develop nuclear weapons, on Thursday handed the IAEA a report with information about is controversial nuclear programme.

It did so a week before an IAEA deadline to allay international concerns over the programme or answer to the UN Security Council, expires on October 31.

According to IAEA spokesman Mark Gwozdecky the inspections team comprises "half a dozen inspectors" and is led by IAEA chief inspector for Iran Ollie Heinonen.

"We are in a new phase and our first priority is to analyze the declaration (by Tehran) to satisfy ourselves that Iran has come clean," Gwozdecky said.

Iran's ambassador to the IAEA, Ali Akbar Salehi, said Friday that Iran in its report to the watchdog admits that it had failed to meet international nuclear safeguards commitments but he again denied that Iran was seeking nuclear weapons.

WAR.WIRE