The theft of up to 30 mailbags from Dublin Airport last night is being investigated by gardaí.
They were taken at 7.40 p.m. from an airport transport buggy before being loaded on an Aer Lingus cargo plane bound for Manchester.
A white Mercedes van is being sought in connection with the incident.
An Aer Lingus spokesman said the contents of the bags were standard mail and that such occurrences were "extremely rare".
He said the incident took place at a "landside area" which has public access and not at an "airside area" for aircraft.
