It was a distinctly Floridian twist: a sheriff in the southeastern US state known for its love of guns has warned residents not to shoot at Hurricane Irma after an online prank promoting the idea went viral.

"To clarify, DO NOT shoot weapons @ #Irma," the office of the sheriff of Pasco County, on the state's west coast, tweeted late on Saturday as the storm made landfall.

"You won't make it turn around & it will have very dangerous side effects" the message added, in reference to the unpredictable flight path shots fired may follow.