Greek police say a bomb has exploded in central Athens near the office of an opposition Socialist party official, causing damage but no injuries.
The explosion comes little more than a week before Greece holds parliamentary elections, called two years early.
Police spokesman Panagiotis Stathis says anonymous calls were made to a Greek newspaper and television station before the explosion warning that a bomb had been planted, and that authorities had evacuated the area.
He said explosives experts were heading to the area to determine what kind of device had been used in the attack.
Local media said the explosion occurred near the office of Socialist party official Louka Katseli, who is the party's representative for the economy.