Athens: A makeshift bomb damaged the office of a far-right group in central Athens early on Friday but no one was hurt, police said.
"A makeshift time-bomb exploded outside the office of Golden Dawn, there are no injuries," a police official said.
Police said there was no claim of responsibility for the blast on the fifth floor of the building near the central Athens Omonia square.
There has been a series of gas canister and bomb attacks by leftist and anarchist groups in Greece since the fatal police shooting of a teenager sparked the country`s worst riots in decades in December 2008.
Police said there was a warning call to a newspaper about a suspect box placed outside the office of ultra nationalist group Golden Dawn.
"All these actions serve as negative arguments for our country," government spokesman George Petalotis told Greek TV Sky.