A bomb exploded on Wednesday near the Acropolis, apparently targeting the house of a Greek shipowner, a police source said, adding that there were no immediate reports of injuries.
"An anonymous caller contacted a Greek daily at 8:10 pm (1810 GMT) and said the bomb would explode at 8:30 pm outside the home of shipowner (Nikos) Tsakos," the police source told AFP.
"The police evacuated the area and so far there are no reports of injuries," the source added.
The bomb had been left in a black backpack outside the entrance of the building, the police source said.
The location of the attack is near the Odeon of Herod Atticus and a few hundred metres beneath the Acropolis, an area very popular with tourists.
The Tsakos group is one of Greece's main shipowning companies. Nikos Tsakos, 50, is the son of group founder Panagiotis Tsakos, the police source said.
Nikos Tsakos has served on the board of directors of the Bank of Cyprus, which has been swept into the financial crisis engulfing the neighbouring island.
Desperate Cypriot savers and businesses have been left with limited cash for nearly two weeks owing to a general bank lockdown to prevent a run on deposits.
A small bomb had exploded outside a Bank of Cyprus branch in Limassol, Cyprus on Sunday.