The Federal Bureau of Investigation (FBI) said on Thursday it is investigating the false threat of a so-called “dirty bomb” allegedly aboard the Maersk Memphis containership in the Port of Charleston, according to Reuters.
The false alarm caused the shutdown and evacuation of the South Carolina port on Wednesday night into Thursday morning until a thorough inspection of four suspect containers on the ship established there was no threat.
FBI involvement stems from the fact that it is a federal crime to make threats against a US-flagged ship such as the Maersk Memphis.
Dirty bombs are weapons improvised from radioactive nuclear waste material combined with conventional explosives. They are also known as radiological dispersal devices (RDDs).