NEW YORK (CBSNewYork) -- New details were emerging Thursday about a terror threat that is having an impact on travel across the globe.
As CBS 2's Sonia Rincon reported, the concern is that al Qaeda in Yemen is developing a bomb that could get around traditional airport security outside of the U.S.
The U.S. Department of Homeland Security issued an alert Wednesday night, just two days before the Fourth of July.
"This directive covers foreign airports in Europe, Africa and the Middle East, and could include additional screenings, swabs of flyers and baggage used to detect explosives," said U.S. Rep. Carolyn Maloney, D-N.Y.
The Arabian Peninsula branch of al Qaeda was responsible for the underwear bomber on a flight to Detroit in 2009. A year later came an attempt to get explosives into printer cartridges on cargo flights bound for Chicago.
Maloney said security overseas will focus on finding potential nonmetallic explosives that might go undetected.
"The troubling part is that we have to be right every second -- every time," Malooney said. "A terrorist can only be right once."
The additional security is described as both seen and unseen. But some of the passengers who spoke to CBS 2 on Thursday as they arrived on overseas flights from Europe were definitely noticing the more thorough security as they boarded flights for the U.S.
Megan Demartinis remembered a little extra attention from screeners in London.
"Like, a really extensive pat-down; very thorough," Demartinis said.
"They definitely photographed us. I had to take my glasses off, and my scarf. It was, you know -- they had to match us up with our passport photos," said traveler Samara Bay.
"On the Madrid end, it absolutely seemed more secure," said traveler Leilani Greag. "Last time, I think we did a quick check-in. It probably took about half an hour. Today, they asked a lot more security questions."
None of the passengers said they minded the extra screening. They were glad to be back safe and stateside for the Fourth of July.
More than 250 international airports have direct flights to the U.S. All of them could see the increased security measures.
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