The backdrop for a Democratic National Convention tribute to U.S. military veterans was apparently a fleet of Russian warships.

The event occurred on the final night of last week’s convention when retired Adm. John Nathman paid tribute to veterans, in front of a gigantic screen that showed what appears to be ships from the Russian Federation Navy, according to The Navy Times.

At least two experts told the publication they were certain the ships were Russian and that the backdrop image appears to be a composite photo that includes U.S. trainer jets flying overhead.

The background shows four ships with radar designs apparently not used in the U.S. fleet.

Navy veteran Rob Barker reportedly detected the apparent mistake and notified The Navy Times. He said his assignment as an electronics warfare technician included the identification of foreign ships by their radars.

The Democratic National Convention Committee was contacted Wednesday but did not comment.

 “The ships are definitely Russian,” said author Norman Polmar, a naval and aviation expert. “There’s no question of that in my mind.”