Updated

WASHINGTON -- The Transportation Security Administration says airline passengers won't get out of body imaging screening or pat-downs based on their religious beliefs.

TSA chief John Pistole told the Senate Homeland Security Committee on Tuesday that passengers who refuse to go through a full-body scanner machine and reject a pat-down won't be allowed to board, even if they turned down the in-depth screening for religious reasons.

"That person is not going to get on an airplane," Pistole said in response to a question from Sen. John Ensign, R-Nev., on whether the TSA would provide exemptions for passengers whose religious beliefs do not allow them to go through a physically revealing body scan or be touched by screeners.

Civil rights groups contend the more intensive screening violates civil liberties including freedom of religion, the right to privacy and the constitutional protection against unreasonable searches.

The issue is getting new attention after a man posted an item online saying he was thrown out of the San Diego airport for rejecting a full-body scan and pat-down groin check and instead insisting on passing through a metal detector.

Pistole acknowledged the incident was drawing wide attention but told the committee an officer involved was "very cool, calm, professional" in dealing with the passenger.

The Electronic Privacy Information Center is among several civil liberties groups suing the TSA in federal court to stop use of the full-body scanners. Their lawsuit says the machines are overly intrusive and violate civil rights, and that it is questionable whether they can detect powdered explosives such as those used by a passenger in last year's attempted Christmas airliner bombing. They also question whether the machines pose a health risk.

"There's a very strong sense right now that the public attitude on the airport body scanner program has swung dramatically," said Marc Rotenberg, director of EPIC. There is growing opposition from civil rights groups, religious organizations, libertarians, airline passengers and pilots, he said.

EPIC is urging air travelers to take part in a national opt-out day the day before Thanksgiving, refusing to go through the full-body detectors and insisting that any pat-down they receive as a result take place in full view of other passengers.

Several senators asked Pistole to address public criticism of the body-imaging machines and more intrusive pat-downs the agency is using. Pistole said the tougher screening is necessary, and that the FDA has found the imaging machines to be safe. Going through the whole-body scanning machine is similar to getting about three minutes of the radiation that passengers receive at 30,000 feet on a typical flight, he said.

Pistole said his agency was working to address pilot and flight attendant concerns about the screening.