VIENNA - UN nuclear inspectors showed new satellite imagery on Wednesday indicating that two side buildings had been dismantled and other possible clean-up work undertaken at an Iranian military site they want to visit, Western diplomats said.

One image from Friday showed signs that "ground-scraping activities" had taken place at the Parchin facility, as well as the presence of bulldozers, according to diplomats who attended a closed-door briefing by UN nuclear agency officials.

This will probably strengthen Western suspicions that Iran is "sanitizing" the site of any incriminating evidence before possibly allowing inspectors of the International Atomic Energy Agency (IAEA ) into the complex.

"They clearly think they have something to hide," one Western envoy said.

The Parchin complex is at the center of Western suspicions that Iran has been developing a nuclear weapons capability despite Tehran's repeated denials of any such ambition.

Last week, the IAEA said in a report issued to member states that satellite images showed "extensive activities" at the facility southeast of Tehran - in what diplomats said was an allusion to suspected cleaning there.

At Wednesday's briefing for diplomats accredited to the Vienna-based agency, IAEA Deputy Director General Herman Nackaerts presented satellite images from November, April and earlier this month, participants said.

The image from Friday indicated that two or more small side buildings - adjacent to the main structure that is of interest to the UN agency - had been removed, diplomats said. One said this suggested that "serious work" was being carried out there.

Nackaerts did not elaborate on what he believed was happening at the site, apart from reiterating that the agency needed to go there to clarify the issue, diplomats said.

Iran, which denies Western accusations it is seeking to develop nuclear weapons capability, has dismissed charges aired about Parchin as "childish" and "ridiculous".

An IAEA report last November found Iran had built a large containment vessel in 2000 at Parchin in which to conduct tests that the UN agency said were "strong indicators of possible (nuclear ) weapon development."

It said a building was constructed "around a large cylindrical object." A large earth berm between the building containing the cylinder and a neighboring building indicated the probable use of high explosives in the chamber.

The IAEA said the vessel was designed to contain the detonation of up to 70 kilograms of high explosives.

Last week, Iranian media said the IAEA had not yet given good enough reasons to visit Parchin, which Iran says is a conventional military site beyond the writ of nuclear inspectors.

"The reasons and document have still not been presented by the agency to convince us to give permission for this visit," the head of the Atomic Energy Organization of Iran, Fereydoun Abbasi-Davani, was quoted as saying by Fars news agency.