NEW YORK (CBS 2/1010 WINS/WCBS 880) -- Intelligence on threats from inside Yemen against a Jewish center in Chicago had authorities on high alert Thursday night into Friday when a quick chain of events sent them scrambling.
Two packages filled with explosives were intercepted in Dubai and the United Kingdom before they could reach their destinations – a pair of synagogues in Chicago, CBS 2's Lou Young reported.
President Barack Obama said al-Queda's presence in Yemen continues to be a real threat to the U.S.
"We also know al-Queda in the Arabian Peninsula based in Yemen continues to plan attacks against our homeland, our citizens and our friends and allies," Obama said.
PHOTOS: US Cargo Plane Terror Probe
CBS 2's Hazel Sanchez reports on the all-day security scramble
That threat sparked searches in Brooklyn, Newark and Philadelphia, and a United Arab Emirates Airline passenger plane was escorted by military jets to JFK Airport as a precaution. FBI officials said there was no known threat from the Emirates flight.
The passengers on Emirates flight EK201 knew nothing about being escorted by fighter jets until they landed at JFK, 1010 WINS' Carol D'Auria reported.
1010 WINS reporter Carol D'Auria talks with passengers after disembarking the plane from Dubai
"Were there fighter jets, really? I didn't notice that at all," David Packles told reporters including CBS 2's Derrick Dennis.
"The only thing that was a little bit different was once we got off the plane, there were cops just all over the place. Seemed like they were waiting for us," Packles said.
"Thank God the security is good and we landed safely -- so it's all good you know," Rajiv Singh told D'Auria.
Early Friday, there were tense moments as a UPS plane was searched for a possible explosive device in a remote location of Newark Liberty International Airport.
WCBS 880's Levon Putney reported that the scene was filled with sirens, flashing lights and officers on stand by as they searched for a device.
WCBS 880 reporter Levon Putney has the story from New Jersey.
Authorities located the package in question, which originated in Yemen, but found nothing. That plane was cleared and flew to UPS' main hub in Louisville, Ky., on its usual route.
Some passengers arriving in Newark began hearing about a potential terrorist threat on their planes.
"Only when we landed, my colleague got an alert email that there was some security risk here at Newark," passenger Kim Queren told CBS 2's Christine Sloan.
CBS 2's Christine Sloan reports from Newark Airport
Some passengers said they were nervous even though the focus was on a cargo plane. Others said they were confident that airport authorities were doing what they could to keep the skies safe.
"We're always concerned about flying. There is more upbeat talk about threats at the moment. Police are being more vigilant," Tony Whelan of London said.
CBS 2's John Slattery talks with passengers from the Emirates flight
"I think we have good security -- certainly with what they put us through in terms of our laptops, liquids, shoes, etc. I think it's a pretty effective security system we have," June Bray said.
The Department of Homeland Security, in a statement, said to anticipate heightened cargo screenings, canine teams and pat downs, WCBS 880's Catherine Cioffi reported.
Kathleen Maloney of 1010 WINS spoke to some passengers at Newark as well who said they were concerned by the security threat posed by cargo planes.
1010 WINS' Kathleen Maloney reports from Newark Airport
"I guess you could do as much damage with a cargo plane as you could with a passenger plane," one man said.
In a separate incident, Police Commissioner Ray Kelly said the NYPD removed a package from a UPS truck in Brooklyn, tested it for possible explosives and found it not to be dangerous.
Kelly said the package was an envelope that came from Yemen, apparently containing bank receipts, and was addressed to the JP Morgan Chase bank in Brooklyn, 1010 WINS' Stan Brooks reported. The package arrived on a plane that landed at Kennedy Airport, Kelly said.
1010 WINS' Stan Brooks with comments from Kelly
Tony Santiago said he literally stepped into a larger-than-life scene on his way to work.
"I saw a lot of chaos when I came out the train station," Santiago told CBS 2's Pablo Guzman.
CBS 2's Pablo Guzman reports from Brooklyn
Also Friday, authorities converged on a Manhattan-bound entrance to the Queensborough Bridge just after rush hour. An NYPD spokesman said a package was removed, and taken to Brooklyn to be examined before the all-clear was given.
Congressman Peter King told CBS 2's Marcia Kramer that "all the evidence suggests that al Qaeda in the Arabian Peninsula" was responsible for the explosives that were discovered in London and Dubai. King added that he would be "very surprised" if it was anyone else.
CBS 2's Marcia Kramer with Rep. Peter King
"This was a real plot, these were explosives...we're not certain if this is the end of the plot [hence] the investigation and our response to it is ongoing," King told WCBS 880.
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