MICHELE NORRIS, host:
In response to the arrests in Britain, the U.S. has for the first time invoked the nation's highest terror alert, the level red, for all flights coming into the United States from the U.K. They've also tightened security for all U.S. air travel, including banning passengers from carrying any liquids or gels on board. Authorities say they have no indication of any plotting within the United States, but that they're taking the steps as a precaution.
Here's NPR's Pam Fessler.
PAM FESSLER reporting:
Homeland Security, intelligence, law enforcement and transportation officials worked through the night to put the new security measures in place. Homeland Security Secretary Michael Chertoff said U.S. authorities had been tipped off by the British about two weeks earlier that the alleged plot appeared to be targeting flights coming into the United States. He said the decision to go to code red was made in part because of what officials admit they still don't know.
Mr. MICHAEL CHERTOFF (Department of Homeland Security): I think it's a recognition of the fact that particularly in this stage of the arrest and the takedown, there's sufficient uncertainty about whether the British have scooped up everybody.
FESSLER: And that it's prudent to consider the risk to aviation extremely high. Because of the nature of the alleged plot, which Chertoff called extremely sophisticated and well-planned, airline passengers on U.S. domestic and international flights will be prohibited from taking any liquids on board, things such as beverages, shampoo, creams and gels.
Mr. CHERTOFF: Any liquids or gels have to be checked as part of baggage to go into the hold. There will be exceptions for baby formula and medicines, but travelers must be prepared to present these items for inspection at the checkpoint.
FESSLER: Chertoff said the prohibitions will be in place until transportation authorities can reassess current screening processes. But authorities acknowledge that being able to deploy technology to detect liquid explosives at the airport checkpoint could be a long way off.
Other security measures were also announced, including more canine detection teams and stepped-up screening of international passengers by Customs Officials. There will also be additional Federal Air Marshal teams on flights coming to the United States from Great Britain.
Transportation Security Administrator Kip Hawley asked passengers to be patient and to help by not putting too much in their carry-on luggage.
Mr. KIP HAWLEY (Transportation Security Administration): That is something very easy to do as you pack your bags. Leave the liquids at home. Drink them. De-clutter your bag. And last, I'd say, enjoy your trip.
FESSLER: He and other officials insisted that U.S. air travel remains safe, in part because of the new security measures. Michael Greenberger, a homeland security expert at the University of Maryland, said that's why terrorists are still clearly intent on targeting aviation, to shake that confidence.
Mr. MICHAEL GREENBERGER (University of Maryland): To the extent you can pull off a dramatic event such as the simultaneous explosion of aircraft as they're crossing the Atlantic, you are achieving the objective of terrorism, which is to instill unreasoned fear in the civilian population.
FESSLER: Greenberger, who's often a critic of the administration's counterterrorism policies, applauded today's moves, in part because of how far along the plot appears to have gone. Homeland Security Deputy Secretary Michael Jackson said in a phone call with reporters that those arrested were not in the process of executing their plans, but they were very close.
President Bush, who was in Wisconsin today, said the arrests were a reminder that the nation still faces a threat from what he called Islamic fascists.
Pam Fessler, NPR News, Washington.