"The task of verifying the declaration begins," spokesman Mark Gwozdecky told AFP.

He said "half a dozen inspectors", led by IAEA chief inspector for Iran Ollie Heinonen, would be leaving Vienna Saturday.

"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 delivered a report to the UN nuclear watchdog Thursday, just a week ahead of an IAEA deadline to prove it is not secretly developing atomic weapons.

Gwozdecky said inspectors would be looking into the possible making of highly enriched uranium that could be used to make a nuclear bomb, whether centrifuges were used to do this, where traces of highly enriched uranium found by inspectors had come from and why Iran was interested in a laser program which could be used in weapons production.

A Western diplomat close to the IAEA said the inspectors would "go back to talk to people, talk to scientists, compare notes, ask follow-up questions and do more environmental sampling" to verify the Iranian report.

The bound document, one-and-half-inches thick, was handed over to IAEA chief Mohamed ElBaradei on Thursday by Iran's ambassador to the IAEA, Ali Akbar Salehi.

Salehi said it "fully discloses all our past peaceful activities in the nuclear field".

ElBaradei said Thursday the IAEA now had to "immediately start all our verification activities and to reconstruct the full history" of Iran's nuclear program.

He said that after verifying the information Iran had provided, "I hope we will come to the conclusion that we have seen all past nuclear activities in Iran."

Non-compliance by Iran with the IAEA's deadline of October 31 could lead the nuclear watchdog to take the issue to the UN Security Council, which could then impose punishing sanctions on Tehran.

The IAEA board of governors is to meet November 20 to hear ElBaradei's latest report on Iranian compliance.

WAR.WIRE