A bomb exploded outside a ship owner's house near the Acropolis in central Athens on Wednesday night, causing damage but no injuries, police said.
The explosion near the country's most famous monument occurred at about 8:30 p.m. (1830 GMT), following a warning call to a Greek newspaper.
Police spokesman Panagiotis Papapetropoulos said officers were able before the blast to evacuate one or two people from the building and to seal off the area of the major tourist site.
The identity of the ship owner was not immediately known.
There was no immediate claim of responsibility for the attack.