The alert stressed that there is no intelligence about an active terror plot, but travelers may notice airport screeners taking a closer look at empty insulated containers.
The Transportation Security Administration "is carefully monitoring information related to terrorist tactics" in coordination with other nations, TSA spokeswoman Sterling Payne said in a statement Thursday. "The possible tactics terrorists might use include the concealment of explosives inside insulated beverage containers, so in the coming days, passengers flying within and to the U.S. may notice additional security measures related to insulated beverage containers."
Payne urged the public "to remain vigilant and aware of their surroundings and report any suspicious activity to their local authorities."
Homeland Security regularly alerts law enforcement about evolving terror tactics as counterterrorism officials learn about them through intelligence chatter.