RENEE MONTAGNE, host:
This is MORNING EDITION from NPR News. I'm Renee Montagne.
News continues to unfold as authorities in Britain and the U.S. reveal more details of what they described as an advanced plot to blow up airplanes flying across the Atlantic. We're joined our studio by NPR's Ari Shapiro, who spent the morning following events. And, Ari, you have a wrap-up of what we know so far.
ARI SHAPIRO reporting:
That's right, Renee. British officials began the operation last night, and by this morning they had arrested 21 people. Police said they were homegrown. Home Secretary John Reid described the difficult decision to act.
Mr. JOHN REID (British Home Secretary): Move too early, you may not know the full scope of who are involved, and you may provoke those you don't know into taking the very action you want to avoid. And move too early and not have immediate success, and you stand to be criticized by everyone. Don't move, and you run the risk of terrible consequences and you will then be more condemned by everyone.
SHAPIRO: The plotters allegedly planned to blow up airplanes in mid-flight using liquid explosives hidden in carry-on bags. British aviation officials banned carry-on baggage today. American airports have prohibited passengers from taking liquids on airplanes with them in carry-on bags. That includes toothpaste, lotion, drinks, everything but medicine and baby formula.
Homeland Security Secretary Michael Chertoff said Americans should not change their travel plans, but he urged people to be vigilant.
Mr. MICHAEL CHERTOFF (Homeland Security Secretary): There is no - currently no indication of any plotting within the United States. Nevertheless, as a precaution, the federal government is taking immediate steps to increase security measures with respect to aviation.
SHAPIRO: For the first time ever, the Department of Homeland Security raised the threat level to red, or severe, for flights between the U.S. and the UK. Meanwhile, details continue to emerge about the alleged plot and those who would carry it out. Secretary Chertoff:
Mr. CHERTOFF: This operation is, in some respects, suggestive of an al-Qaida plot. But because the investigation is still underway, we cannot yet form a definitive conclusion. We're going to wait until all the facts are in.
SHAPIRO: Some of the hallmarks of al-Qaida include timed explosions, especially on airplanes - as was apparently the case in this alleged plot. Chertoff described this plot as sophisticated. He said it had a lot of members and it was international in scope.
British authorities have described the day's events as the first stage in an ongoing investigation. They say they're convinced that the main players in the alleged plot have been arrested, but there may yet be others.
In airports on both sides of the Atlantic, flight cancellations and delays caused backups. Authorities say these are very serious and inconvenient measures that they're taking, but they emphasized that they'd rather have more protection and scale those policies back once they're no longer necessary.
MONTAGNE: Ari, thank you. That's NPR's Justice reporter Ari Shapiro joining us in our studio as events unfold. Transcript provided by NPR, Copyright NPR.
