The International Atomic Energy Agency says it has discovered traces of processed uranium at a second site in Syria.
The UN agency has been examining US intelligence reports that Syria had almost built a North Korean-designed nuclear reactor meant to yield weapons-grade plutonium before Israel bombed it in 2007.
Inspectors who found uranium particles at the remote desert site a year ago also found similar traces at a small research reactor in the capital, Damascus.
The IAEA said in February that inspectors had found enough traces of uranium in soil samples taken from the bombed site a year ago to constitute a significant find.
The latest report on Friday said "anthropogenic natural uranium particles" had also turned up in environmental swipe samples taken from hot cells of a miniature neutron source reactor facility in Damascus.
The IAEA previously said satellite pictures taken before the Israeli bombing revealed a building resembling a reactor.