Dublin Airport officials later cleared the Boeing 767-300 traveling from Istanbul, Turkey, to continue its journey to New York's John F. Kennedy Airport after determining that the suspected bomb was just an unattended mobile phone and charger.
Irish Aviation Authority spokeswoman Lilian Cassin said the pilot requested an emergency landing, the aircraft landed without incident and was diverted to an isolated corner of the runway.
Ireland's national police force, the Garda Siochana, said officers boarded the plane, spoke to the pilot about the nature of the suspected bomb, and asked any passenger missing their phone to come forward.
It was determined that the passenger had decided to charge the phone using the restroom's socket for shavers and left it there, wrapped up in its charging cord, and another passenger using the restroom reported it might be a bomb.
Police said nobody was hurt or arrested because of Monday's security alert, and the Dublin Airport Authority said no other flights were affected.
Delta spokesman Anthony Black said the aircraft had 208 passengers and 11 crew members. He said the aircraft was refueled to continue its journey later Monday.