A bomb went off at the offices of a Greek ultra-right group near Athens early on Tuesday causing damage but no casualties,a police source said.
The explosion occurred at the local offices of the Golden Dawn party in the Athens suburb of Aspropyrgos. "It was a powerful blast that caused a lot of damage," said a police official who declined to be named.
Riding a wave of public anger at austerity, corrupt politicians and illegal immigration, Golden Dawn has come out of nowhere to becomeGreece's third-biggest party, according to the latest opinion polls.
A survey by VPRC, an independent polling company, put its party's support at 14 percent in October, compared with the 7 percent it won in elections in June.
Several Greek observers and politicians said Golden Dawn should be declared illegal because its rhetoric and emblems resemble the Nazi party and Greece's 1967-1974 military junta.
The party, however, denies any such resemblance.