UN nuclear inspectors have found traces of weapons-grade uranium in Egypt, the International Atomic Energy Agency said in a report obtained Wednesday by The Associated Press. Dated May 5, the restricted report said IAEA inspectors detected the particles last year and in 2007. A senior diplomat accredited to the agency said that it was the first time the traces were reported by the Vienna-based nuclear monitor. He demanded anonymity for commenting on the restricted document. It was unclear why the agency was disclosing the findings now. IAEA spokespeople did not immediately return calls asking for comment. In its page-long section on Egypt, the 82-page document said Cairo believes the particles could have come into the country on containers with radio isotopes but said the IAEA was continuing its investigations because "it has not yet identified the source of the uranium particles." Both high- or weapons-grade and low-enriched uranium can be used to make radio isotopes, which are used in medicine and scientific research. The report said traces of low-enriched uranium also were found at the same site - Inshas, northeast of Cairo, where Egypt's two small research reactors are located. But highly enriched uranium can be turned into the fissile core of nuclear warheads. Concerns that Iran could reconfigure its present nuclear program that is churning out low-enriched uranium for reactor fuel to instead produce highly enriched uranium have led to U.N. Security Council sanctions against Tehran. The Egyptian Embassy in Vienna said the ambassador was in Cairo and unavailable for comment. An embassy diplomat said there would be no comment "because the report only appeared yesterday" on the IAEA's restricted intranet site "and we only sent it to Cairo for studying today." He refused to give his name on the phone, saying he was not authorized to talk to reporters on the issue. It was unclear whether the environmental samples that revealed the traces were part of a new investigation or linked to a major IAEA probe launched after disclosures in 2004 that Egypt failed to report nuclear experiments and related activities that could potentially be used for either nuclear civilian or weapons programs. In a report published the following year, the agency described the work as small-scale, saying the programs took place decades ago and did not appear to be part of an attempt to make nuclear weapons. Still, it faulted Egypt for keeping them secret, despite obligations to report them to the IAEA. Throughout that inquiry Cairo claimed that its scientists were driven by interest in exploring the nuclear fuel cycles for creating energy and characterized the lack of reporting as sloppiness. In Wednesday's report, the IAEA said its inspectors planned to take additional samples at Inshas in an attempt to clear up the origin of the enriched uranium.