Workers at the scrap yard in Tampa called police to say they'd found a "torpedo", reports Metro News.

Experts from nearby MacDill Air Force Base quickly identified the object as a Patriot anti-missile-missile. They said that it was harmless because it did not have a  warhead, but it still had its rocket motor and guidance system.

Air force spokesman Lt. Omar Villarreal confirmed that the missile did not contain "the part on top that goes boom".

Patriot missiles are the main surface-to-air missile system used by the American military, and first came to prominence when they were used to shoot down Iraqi Scud missiles during the 1991 Gulf War.