"An anonymous call to a TV station warned that an explosive device on a parked motorcycle outside the court house would go off in about 40 minutes," said a police official who did not want to be named.
Police evacuated the building before the blast, the official said.
Authorities believe a makeshift explosive device was placed on a motorbike parked outside the Athens courthouse, the facade of which was damaged by the blast.
Windows of buildings across the street were shattered and at least eight cars were damaged. There was no immediate claim of responsibility.
"It was a huge blast. I was in the kitchen with my grandchild and the whole building shook. We saw smoke and flames," an elderly woman who lives about 50 meters from the courthouse told Flash radio.
"We condemn the action, there is no point in trying to change the world by risking the death of innocent people," Deputy Transport Minister Spyros Vougias told Skai TV.
The police official said the fact that the caller gave a 40 minute warning along with the motorcycle's plate number indicated the perpetrators were not aiming to kill.
Greece has a decades old history of leftist violence. Some groups became more active after riots in December 2008, triggered by the police killing of a teenager. They usually target government buildings, police stations and banks, mostly at night, and make warning calls.
In November, a Greek anti-capitalist group claimed responsibility for sending parcel bombs to a number of embassies in Athens and to foreign governments abroad.
reuters
http://www.reuters.com/article/idUSTRE6BT0PR20101230
