The FBI said today it was reminding law enforcement officials of what it called terrorists' continued interest in downing airliners with explosives hidden in shoes and clothing.
"The FBI possesses no information to indicate a specific plot to use concealed explosives against commercial airlines," the bureau said in a weekly advisory sent to authorities. "However, law enforcement should remain alert to the possibility."
The bulletin, a summary of information culled from counter-terrorism investigations and analysis, said terrorists had a "continued interest in targeting airlines".
The alert was tied to the first anniversary of a plot by Richard Reid, a British citizen, to blow up a transatlantic flight to the United States using explosives hidden in his shoes, said an FBI spokesman.
Reid was overpowered by passengers and crew aboard a Paris-to-Miami American Airlines flight after he was spotted trying to ignite a fuse in his shoe. The flight was diverted to Boston, where Reid was taken into custody.