Gardaí are askingthe public to reportbank notes covered in red dye that may be circulating followinga robbery at the An Post office in Cork Street today.
Two masked men armed with knives forced their way into the office on Cork Street as it was opening at around 9 a.m.
They escaped with several thousand pounds in cash after forcing the manager to hand a money box over and escaped in a stolen car, which was found abandoned nearby.
A garda spokesman said they believe the men may be covered in the red dye, which was found sprayed in the car. It was activated when the box was forced open.