Twelve passengers arriving at Philadelphia International Airport on international flights were experiencing flu-like symptoms, the airport said Thursday.

The passengers fell ill after traveling with American Airlines 755 from Paris and American Airline 1317 from Munich.

"As a precaution, all passengers on the two flights -- totaling about 250 plus crew -- were held for a medical review and the Centers for Disease Control (CDC)," according to a statement issued by the airport.

The CDC, the Philadelphia Health Department and the Philadelphia Fire Department personnel performed medical evaluations and assessments, the airport said.

"The passengers -- except for the 12 affected -- are in the process of being released," it added. "Airport operations were not impacted during this time."

A CDC official said none of these passengers are "severely" ill, according to local reports.

More details will be released as test results are confirmed.

The incident 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.