Federal officials issued a new warning to airlines Wednesday to be on the lookout for a new generation of terrorist shoe bombers.
The Department of Homeland Security cited credible new threats that explosives hidden in shoes could be used to attack commercial passenger jets.
It told airport screeners to check passengers’ footwear for traces of bomb materials.
Screeners were advised to use detection swabs to test shoes worn by passengers or contained in their carry-on luggage, NBC said.
But there was no indication of a specific bomb plot, officials said.
CBS reported the alert was prompted by intercepted “chatter” about the possible revival of shoe-bomb attacks.
A source told NBC the alert was “an advisory to airlines to be on their A game.”
Intelligence officials gave conflicting accounts about whether the concern over the intelligence was low-level or moderate.
“Something caused DHS concern, but it’s a very low threshold to trigger a warning like this,” a US intelligence official said.
The alert was similar to one issued two weeks ago, which was prompted by fears that terrorists flying to Russia would conceal explosives in toothpaste tubes in a bid to attack targets during the Winter Olympics in Sochi.
The latest warning was focused on flights headed to the United States from abroad.
“Out of an abundance of caution, DHS regularly shares relevant information with domestic and international partners about [threats],” the department said in its new statement. “These types of regular communications are part of that important priority.”
Airplane passengers in the United States have had to take off their shoes at airport security checkpoints since shortly after “shoe bomber” Richard Reid’s abortive bid to blow up a Miami-bound flight in late 2001.