All passengers and crew from two American airlines flights arriving at Philadelphia International Airport on Thursday were held back for medical review after 12 people became ill with flu-like symptoms.
A total of 250 people underwent a medical examination as a precaution, airport spokeswoman Diane Gerace said.
Both of the flights arrived from Europe — one from Paris and the other one from Munich, she said.
It appears that no other flights or airports were affected.
American Airlines spokeswoman Leslie Scott said that the crews did not contact medical personnel ahead of landing to alert them that there were sick passengers on board.
The reported illnesses came a day after at least 19 people aboard an Emirates flight from Dubai to New York were confirmed ill when the aircraft landed at John F. Kennedy International Airport.