MICHELE NORRIS, host:
From NPR News, this is ALL THINGS CONSIDERED. I'm Michele Norris.
MELISSA BLOCK, host:
And I'm Melissa Block.
Authorities have intercepted two suspicious packages that were sent from the Middle East and addressed to synagogues in Chicago. President Obama said this afternoon the packages do contain explosive material and constitute a credible terrorist threat.
President BARACK OBAMA: Although we are still pursuing all the facts, we do know that the packages originated in Yemen. We also know that Al-Qaeda in the Arabian Peninsula, a terrorist group based in Yemen, continues to plan attacks against our homeland, our citizens and our friends and allies.
BLOCK: The president was briefed on the threat late last night, and a frantic examination of cargo shipments followed.
NPR White House correspondent Scott Horsley joins us now.
Scott, you were at a White House briefing on this today. How did authorities say they discovered these packages in the first place?
SCOTT HORSLEY: Well, authorities aren't saying exactly what led them to the packages, but it does not appear to have been a random cargo screening. White House counterterrorism adviser John Brennan was a little cagey about just what intelligence experts knew or when they knew it, but he did say that when you pull on a string, there's a reason you pull on it.
What we do know is that Brennan briefed the president last night about 10:30 p.m. that there was a possible threat. And it was sometime after that these two packages were found - one in England, a second in Dubai. Once these packages were indentified, then a wider search began for other packages that might have come from Yemen.
BLOCK: Now, the president, as we heard, mentioned al-Qaeda in the Arabian Peninsula, that group in Yemen, we would assume that group is the focus or at least a focus of the investigation, right?
HORSLEY: Certainly, a prime suspect. That's right. John Brennan said outside of Afghanistan and Pakistan, al-Qaeda in the Arabian Peninsula is the most active al-Qaeda franchise. This is the group you will remember that was behind the unsuccessful attempt to blow up a passenger jetliner bound for Detroit last Christmas.
What's more? Throughout its history, al-Qaeda has had an interest - some will even say an obsession - in going after trans-Atlantic airplanes. Although in this case, it's not clear whether these packages were designed to blow up in flight or perhaps after they had reached their destination - those synagogues in Chicago.
BLOCK: And, Scott, we mentioned that frantic search of cargo planes that followed this discovery. What has been the effect on cargo and passenger air traffic today?
HORSLEY: Yeah, once that string began to unravel, authorities started looking for other packages from Yemen. That led to a search we know of two cargo planes in Philadelphia and one in Newark. There was even a passenger jet bound for New York this afternoon that got a military escort, simply because it was carrying some cargo from Yemen. It landed uneventfully. There has been a lot of discussion among all the Homeland Security agencies and the air security agencies about additional precautions that need to be taken. So far though, only those two packages have been found to contain anything outside the ordinary.
BLOCK: Yes, Scott, this, of course, comes just a few days before the midterm elections here. The president has a busy weekend of campaigning planned. Is that still on schedule?
HORSLEY: As far as the White House is saying, for now, all of the events are on. The president is appearing tonight in Virginia with a congressional candidate. He's got multiple campaign stops scheduled for tomorrow and Sunday. He is getting regular updates about the investigation here. But the White House is trying to send a message that while we are being alert, we are not going to be cowed by this attempted attack.
Pres. OBAMA: The American people should know that the counterterrorism professionals are taking this threat very seriously and are taking all necessary and prudent steps to ensure our security.
BLOCK: Scott, I'm curious about something. John Brennan, the counterterrorism adviser, you mentioned said at the White House today the United States is not assuming that the attacks were disrupted and is remaining vigilant. How should we read that?
HORSLEY: Well, again, they are tracing other packages that might have come from Yemen. They are not sure whether this was linked to a broader terror attack. One of the things the president has directed intelligence and counterterrorism experts is to see what this might be connected to. John Brennan had a conversation today with the president of Yemen who has pledged their full cooperation in the investigation.
BLOCK: Okay. NPR White House correspondent Scott Horsley, again, talking about the two suspicious packages that were intercepted today both containing explosive material bound from Yemen to synagogues in the Chicago area.
Scott, thank you very much.
HORSLEY: Good to be with you, Melissa.
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