WASHINGTON — — Passengers flying into the United States from Nigeria, Yemen and other "countries of interest" will be subject to enhanced screening techniques, such as body scans and pat-downs, the Transportation Security Administration said Sunday.
Starting today, all passengers on U.S.-bound international flights will be subject to random screening.
In addition, anyone traveling from or through nations regarded as sponsors of terrorism - as well as "other countries of interest" - will be required to go through enhanced screening. The TSA said those techniques include pat-downs, carry-on bag searches, full-body scanning and explosive detection technology.
The State Department lists Cuba, Iran, Sudan and Syria as state sponsors of terrorism. The "other countries" whose passengers will face enhanced screening include Nigeria, Yemen and Pakistan.
Umar Farouk Abdulmutallab, the Nigerian man who allegedly tried to set off an explosive device aboard a Northwest airliner on Christmas Day, has told U.S. investigators he received training and instructions from al-Qaida operatives in Yemen.
The TSA said the ability to enforce the new security measures is the "result of extraordinary cooperation from our global aviation partners."
Federal authorities, working to close security gaps exposed by the thwarted terrorist attack on a Detroit-bound airliner, are multiplying the number of imaging machines at the nation's biggest airports. The devices scan passengers' bodies and produce X-ray-like images that can reveal objects concealed beneath clothes.
Forty units are in use at 19 airports - including four at Baltimore-Washington International Thurgood Marshall Airport - and the TSA said it has ordered 150 more scanners to be installed early this year. It has secured funding for an additional 300.
Passengers selected for a full-body scan can decline, but if they do, they must submit to full-body pat-downs by a TSA officer. The technology was introduced a couple of years ago, but U.S. airports have been slow to install the machines, partly because of privacy concerns raised by some members of Congress and civil liberties groups.
Seeing passengers beset by years of an ever-evolving airport drill - at first handing over belts, cell phones and laptops for screening, then shoes, and later, dealing with restrictions on gels and liquids - some activists and experts are asking how much compliance is too much in the name of homeland security.
"The price of liberty is too high," said Kate Hanni, founder of FlyersRights.org, an advocacy organization for air passengers. She shuttles regularly between her California home and Washington to lobby Congress. Hanni said many of her group's 25,000 members are concerned that "the full-body scanners may not catch the criminals and will subject the rest of us to intrusive and virtual strip searches."
To others, however, the scans are not so bad, and the reason is simple: They're virtual. Passengers walk through the machines fully clothed; the resulting image appears on a monitor in a separate room and conceals passengers' faces and sensitive areas.
"It covers up the dirty bits," said James Carafano, a homeland security expert at the conservative Heritage Foundation.
"I don't think it's any different than if you go to the beach and put on a bikini," said Brandon Macsata, who started the Association for Airline Passenger Rights.
Critics talk as if the machines produce images that are "Playboy-centerfold quality," said Jon Adler, head of the Federal Law Enforcement Officers Association. "I don't consider the full-body scanners an invasion of privacy. I think a bomb detonating on a plane is the biggest invasion of privacy a person can experience."
Dutch security officials have said that full-body scanners could have detected the explosives that Abdulmutallab allegedly concealed in his underwear when boarding a Northwest Airlines flight in Amsterdam. But although the city's Schiphol Airport operates more than a dozen such scanners, none was used to check the Nigerian.
The Netherlands has since announced that it will require all U.S.-bound passengers to pass through full-body screenings. And Prime Minister Gordon Brown said Sunday that full-body scanners will be introduced in Britain's airports.
Last week, the TSA launched a public relations offensive to convince passengers that its latest checkpoint innovation will make airports more secure. "It's a promising technology," spokeswoman Kristen Lee said. "It's designed to detect anomalies."
The issue is almost certain to be the subject of debate when Congress reconvenes this month. The House approved a bill in the summer limiting the use of full-body scanners, but the Senate has yet to take up the matter.
Critics say expanding the use of the machines is something of a knee-jerk reaction. And, experts say, explosives can go undetected if concealed in body cavities.
"It's definitely not a silver bullet," Carafano said. "There's a way to beat it. It's called a 'booty bomb,' where you actually insert the explosive inside the human being and ... detonate [it] with a cell phone."
The TSA has tried to assuage privacy concerns by saying that the digital images produced by the machines would be deleted after passengers clear checkpoints. But critics are not reassured.
"TSA has said, 'Trust us, we've put the switch to the "off" position,' " said Marc Rotenberg, executive director of the Electronic Privacy Information Center. "But it's not difficult to imagine a scenario where they might decide to put the switch to the 'on' position."
The Associated Press and Washington Post contributed to this article.