Experts at a Washington-based research institute say commercial satellite imagery of Syria show construction that resembles the early stages of a small nuclear reactor.

The experts at the Institute for Science and International Security speculate that the site was the target of an Israeli air strike on September 6.

In a report released Wednesday, former United Nations weapons inspector David Albright, who heads the institute, and researcher Paul Brannan say the imagery, which was taken about a month before the Israeli air strike, shows a tall building that may house a reactor under construction. They say it is similar in design to a North Korean nuclear reactor.

The experts say there appears to be a pump station nearby along the Euphrates River, which they say may have been intended to supply cooling water to the reactor. They say trucks and evidence of heavy machinery tracks indicate recent construction activity.

But Damascus has denied the air strike targeted a nuclear facility. Syrian President Bashar al-Assad says Israel targeted an "unused military building."

Israel recently lifted a media blackout on news reports about the raid, confirming that its warplanes hit what it called a "military target" deep inside Syrian territory.