An American Airlines flight from Seoul to Dallas/Fort Worth International Airport was diverted on Tuesday after the aircraft hit severe turbulence.
American Airlines confirmed the diversion and said there are 240 passengers and a crew of 15 on the flight.
There are reports that as many as 15 passengers were injured on board. American Airlines did not confirm those reports.
The flight, AA280, is expected to land at Narita International Airport in Tokyo later Tuesday.
"American's primary concern at this time is for our passengers and crew on board the airplane and our team in Narita is providing assistance," an American Airlines spokeswoman said. "We will provide additional information as it becomes available."
American maintenance personnel are scheduled to inspect the plane at Narita, where it is expected to stay overnight. The flight will continue Wednesday.