There is no evidence the plane was ever in danger, officials said. An examination by two doctors aboard the plane found that the passenger, a French citizen born in Cameroon, had no scars or incisions, said U.S. Sen. Susan Collins of Maine, who was briefed by Transportation Security Administration chief John Pistole.
The FBI and Homeland Security Department warned airlines last summer that terrorists are considering surgically hiding bombs inside humans to evade airport security.
"We have seen intelligence identifying surgically implanted bombs as a threat to air travel," said Collins, the ranking Republican on the Homeland Security Committee.
Two F-15 fighters scrambled to escort Flight 787 with 179 passengers and nine crew members to Bangor International Airport, where it landed shortly after noon.
The Boeing 767 was about 40 minutes away from Bangor when local officials were alerted. After landing, it taxied to a remote part of the airport where law enforcement officials removed the passenger, said Tony Caruso, acting airport manager.
Passengers were advised to keep their shades down during a movie, so they didn't realize fighter jets had been dispatched to intercept the flight, said Stuart Frankel of Baltimore. Also, there were a couple of calls on the overhead speakers for doctors, but that didn't seem especially unusual either, he said.
Eventually, the pilot advised that the jet needed to land for fuel in Maine.
"We saw lots of police and federal customs people take a woman off the plane in handcuffs," Frankel said. "People were amazed at what was going on. We didn't know what was happening until we landed."
Several passengers said they'd noticed that particular passenger because of her slight stature and big eyelashes. They said she attracted attention by walking up and down the aisle throughout the flight.
William Milam from Richmond, Va., said he'd spoken French with the woman and helped her get her luggage into an overhead bin.
After the woman was removed from the flight, passengers were informed that they'd have to leave while the jet was checked for explosives, Milam said. "This is like, 'Wow,'" he said. "I'm thinking drugs. And they're thinking explosives."
The passengers were kept in a secure area before being allowed back onto the jet, which departed 3 1/2 hours later for Charlotte, N.C.
U.S. Rep. Peter King, R-N.Y., who was briefed on the matter, said the woman who was detained was traveling alone without any checked baggage and intended to stay in the U.S. for 10 days.
The FBI, which is conducting the investigation, interviewed passengers before the plane departed.
"At this time, there is no evidence that the plane or its passengers were ever in any actual danger," said Greg Comcowich, an FBI spokesman in Boston.
The TSA issued a statement saying the passenger exhibited suspicious behavior that warranted the unscheduled stop.
"Out of an abundance of caution, the flight was diverted to (Bangor) where it was met by law enforcement," said TSA spokesman Sterling Payne.
The Bangor airport is accustomed to dealing with diverted flights.
It's the first large U.S. airport for incoming European flights and the last U.S. airport for outgoing flights, with uncluttered skies and one of the longest runways on the East Coast. Aircraft use the airport when there are mechanical problems, medical emergencies or unruly passengers.
Home to a Maine Air National Guard unit, the airport also serves as a refueling hub for military aircraft transporting personnel and cargo to and from Europe and the Middle East.
Associated Press writers Eileen Sullivan in Washington; Mitch Weiss in Charlotte, N.C.; David Sharp and Clarke Canfield in Portland, Maine; and Denise Lavoie and Jay Lindsay in Boston contributed to this report.