CAIRO (Reuters) - Egyptair turned flight MS 729 bound for Moscow back to Cairo after a threatening letter was found on one of the seats of the aircraft, Egypt's national carrier said on Wednesday.

       "The flight landed 22 minutes after takeoff and passengers returned safely to the grounds of Cairo Airport where the necessary measures are being taken," the statement said.

       (Reporting by Abdelnasser Aboelfadl and Mahmoud Mourad; writing by Nadine Awadalla; editing by Jason Neely)