A team of six senior inspectors from the International Atomic Energy Agency (IAEA) returned to Vienna on Thursday following the first of a series of in-depth inspection missions, said IAEA spokesman Mark Gwozdecky.

The inspectors "received active and full cooperation from Libyan authorities" throughout their mission, during which they visited nine out of a total of 10 sites declared by Libya as relevant to its nuclear activities.

The 10th site is a storage facility for natural uranium, and will be inspected in the near future, added Gwozdecky.

"In the past two weeks we have acquired considerable information and understanding of the history, scope, and development of Libya's nuclear program," he said.

"However we aren't ready to draw any conclusion, it will require much more and thorough work before we can do so."

The IAEA mission and a visit to Libya at the weekend by IAEA head Mohamed ElBaradei followed Libya's surprise announcement last month that it was giving up any ambitions to acquire weapons of mass destruction and would allow UN inspections of its nuclear sites. The announcement came after nine months of secret talks with London and Washington.

Tripoli pledged during ElBaradei's visit to allow snap inspections of suspect nuclear sites as if it had already signed the additional protocol to the Nuclear Non-Proliferation Treaty.

The IAEA spokesman also responded indirectly to the apparent discontent of Washington, which wants inspections to be conducted by the United States and Britain.

The New York Times on Friday quoted a Bush administration official who called ElBaradei's visit to Libya "a 'badly advised' public relations exercise at a time when the United States Central Intelligence Agency and Britain's MI6 spy agency were developing strong bonds with Libya's military and intelligence chiefs."

"We want to have more conversations in private with the Libyans before doing anything in public," the senior official was quoted as saying this week.

He added that ElBaradei "has (only) got a minuscule percentage of the knowledge" about the full assortment of Libya's illicit weapons programs, therefore "he has a role, but only with the technical aspects" of verifying the dismantling of the Libyan nuclear program .

The same article quoted Libya's Prime Minister Shukri Ghanem as urging Washington to lift sanctions against his country before May 12 -- the deadline for Tripoli to complete compensation payments to the families of the victims of the Lockerbie disaster -- or Libya might not feel obliged to pay the six million dollars that remains to be paid in compensation to families of victims of the 1988 bombing of a Pan American airliner over Lockerbie, Scotland.

Gwozdecky noted the IAEA had exclusive responsibility for verifying the Nuclear Non-Proliferation Treaty. It reacted quickly and had done its work, he said.

For the IAEA the success of any verification hinges on "the authority that the inspectors have", he added.

That is why the UN agency advocates "that all countries sign the additional protocol, and it is here important to know that Libya decided this week to act in accordance with the additional protocol", he said.

In order to better accomplish their task, the inspectors also want any country having information relevant to the IAEA's work to share it with the UN agency.

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