An unidentified woman was seen on a security tape entering the Terminal B boarding area through an exit around 11:10 a.m., Transportation Security Administration spokeswoman Ann Davis said.
The woman was a passenger who left the area, turned around and re-entered through the same exit, then left again 90 seconds later, she said.
''We suspect she walked back through the exit lane inadvertently,'' Davis said. ''Nonetheless, we needed to take all precautions.''
Airport security evacuated the American Airlines portion of the terminal to conduct a sweep. Passengers were re-screened before they were allowed to return to the boarding area around 2 p.m. A total of six flights were delayed.
Davis said the woman apparently left the airport after leaving through the exit door.
''We don't anticipate being able to identify her,'' she said.
