Rhonda Gaynier, a New York real-estate lawyer, was flying home from Tampa, Fla., and passing through airport security (search) when she was asked to step aside for additional screening.

What happened next shocked her: Using an open hand, a security agent touched her on her shoulders, under her arms, around her waist, across her bra strap, and between her breasts, Gaynier said — all in front of other passengers.

"I was almost in tears," she said. "I've never been so humiliated in my life. It's one of the worst experiences I've ever had to endure."

The patdown before that mid-October flight was the result of a new government directive that airport screeners carry out more frequent, and more thorough, searches for explosives.

But women across the nation say the patdowns go too far. Some are so angry that they have stopped flying altogether.

The new policy was implemented by the Transportation Security Administration (search) on Sept. 22, after 90 people were killed in two plane crashes in Russia believed to have been caused by Chechen women who carried explosives on board.

Sommer Gentry, a Massachusetts Institute of Technology graduate student who commutes twice a month from her home in Baltimore, said she now takes Amtrak (search), rather than submit herself to the intrusive airport search.

Gentry said she has had several upsetting encounters with the screeners, and calls the way she was touched "humiliating and deeply offensive."

"I will go to great lengths to avoid flying now, because patdowns make me feel dirty and ashamed," she said. "It just gets worse every time. Now I'm afraid."

The new TSA rules say screeners can select passengers for patdowns based on "visual observations," even if they do not set off metal detectors. Amy Von Walter, a TSA spokeswoman, said screeners are looking for "irregularities in a person's natural shape or contour."

Von Walter said other passengers are selected at random by computer, their boarding passes marked with "SSSS," as in Gaynier's case. In addition, other travelers may get marked "SSSS" because of "passenger behavior," such as paying in cash or frequently buying one-way tickets, according to a TSA official speaking to The Associated Press on condition of anonymity.

The rules stress that passengers can ask to be checked in private and by a screener of their same gender — Gentry and Gaynier say their patdowns were conducted by women — and that screeners must only use the backs of their hands when touching sensitive places.

But legal groups who are monitoring the women's complaints say those rules are not always followed.

"What these women are complaining about is being groped," said Barry Steinhardt, director of the American Civil Liberties Union's technology and liberty project, which is tracking the complaints and hopes to meet with the TSA soon.

Von Walter said the TSA had received about 250 complaints since the new procedures went into effect in September. She said each is being investigated, and "we will take appropriate action as necessary." She did not provide a gender breakdown for the complaints.

She defended the new measures as addressing "a specific threat." She said they are similar to searches conducted by other countries on high alert for terrorism.

The patdowns could be made obsolete by new machines being tested at six airports nationwide that suck in air around passengers and quickly detect explosive material. But that project is two years behind schedule, said Florida Rep. John Mica, a Republican who chairs the House aviation subcommittee.

"My biggest fear is suicide bombers on an aircraft," he said. "We just don't have too many other options than to pat people down to try and detect the explosives."

Another congressman, Massachusetts Democrat Ed Markey, has told the TSA he is concerned the searches are humiliating and are being disproportionately applied to women.

An unofficial Web site where TSA screeners post news and comments brims with remarks from screeners who say the patdowns are a necessary, if uncomfortable, fact of life in an age of terrorism.

"We don't enjoy" the patdowns, "but sadly, past experience shows that terrorists have used every category to attack, wound and kill thousands," A.J. Castilla, a screener at Boston's Logan International Airport, said.

Gaynier, 46, has filed a complaint with the TSA and is exploring legal action against it. She said she has heard from women around the country who object to the searches, many of whom say they are afraid or embarrassed to complain.

"Post-9/11, we have all come to accept a certain level of inconvenience and intrusion," she said. "I will tolerate that. But you want to touch my body, you better have a damn good reason, and they don't."