A man with a hacksaw blade and a razor blade in his shoe was arrested yesterday at Miami international airport.
Police said Mr David McIntyre (38), who was traveling with his wife and children, set off metal detectors as he tried to board a flight.
"He had a hacksaw blade and a razor blade in his shoe," a Miami -Dade police spokesman said. "He has been charged with carrying a concealed weapon."
It was unclear why the man, from Westchester in Pennsylvania, was carrying the blades in his shoe.
The United States has stepped up security procedures after the terror alert status was raised to the second-highest level on Sunday as threat indicators reportedly became greater than at any other time since the September 11, 2001, airliner attacks.
US Homeland Security Secretary Tom Ridge said the al-Qaeda network of Osama bin Laden might try to use aircraft again in new attacks.