Boston Emergency Medical Services' Twitter page says 13 of the ill passengers were taken to the hospital Sunday morning after the plane landed.
Massachusetts Port Authority spokeswoman Samantha Decker says the passengers' symptoms appeared mild. She said she didn't have information on what may have caused the illnesses.
An American Airlines spokesman said they were part of a student group. He said no other passengers or crew members felt ill.
The flight landed at Boston Logan International Airport on Sunday morning.
This story has been corrected to show that 13 passengers went to the hospital, not 16.
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