A Japanese tourist accidentally caught a UFO on video as it flew over an ancient mosque in Iran. What is it?

The tourist claims the unidentified flying object was not noticed until after the footage of a tour of the Sheikh Lotfollah mosque was reviewed later. Just a short clip of the original video was posted to YouTube, followed by an enhanced enlargement.

The object flying overhead is a disc-shaped craft, silver in color, with no wings and no navigational lights or identifying markings.

The object is clearly a metallic disk.  To read more and view the video, click here.