Police reported finding a suspicious package at a security checkpoint in Terminal D shortly after 5 a.m., The Miami Herald reported.
The area was evacuated, forcing passengers to cram into other checkpoints in the terminal. Traffic at the terminal was halted as well.
The checkpoint was reopened and airport operations returned to normal about 7:30 a.m., officials said.
Airport spokesman Greg Chin said he was told the suspicious package was a novelty lighter that was shaped like a grenade.
Shortly after the checkpoint reopened, Chin sent out a media alert that said: "Please advise your readers and viewers to not travel with novelty items that look like weapons."
The passenger who was carrying the lighter will not face charges, WTVJ, Miami, reported.