The U.N. nuclear watchdog agency says its inspectors have found traces of weapons-grade uranium in Egypt.

A restricted report from the International Atomic Energy Agency says the particles were detected last year and in 2007, and remain under investigation.

A senior diplomat who demands anonymity for commenting on restricted information said Wednesday it's the first time the agency has reported these findings.

The report also says the highly enriched uranium particles were found alongside traces of low-enriched uranium particles. Both were detected at the Inshas site, northeast of Cairo, where Egypt's two small research reactors are located.

The document said Egypt believes the particles could have come into the country on containers containing radio isotopes.