FILE PHOTO: A police officer searches for evidence after a bomb blast at a Court building in Athens, Greece, December 22, 2017. REUTERS/Costas Baltas

ATHENS (Reuters) - A Greek urban guerrilla group claimed responsibility on Wednesday for a blast at an Athens court on Dec. 22, accusing the judiciary of acting as a proxy for politicians supporting austerity in the crisis-hit country.

Nobody was injured in the early-morning blast at the Athens Court of Appeal. The explosion shattered windows and damaged the facade of the building. Shots were also fired in the direction of a security guard present.

In a statement, the Group of People’s Fighters (OLA) said the Court of Appeal had upheld the legality of austerity measures, such as cutting pensions and salaries, in return for bailouts from international creditors.

“Justice is like a snake. It will only bite those barefoot,” the group said in a proclamation.

Police said they believed the claim was authentic.

The group has previously claimed responsibility for a blast outside the offices of a Greek business federation in Athens in 2015 and two attacks in 2013 - one on the headquarters of Greece’s conservative New Democracy party and another on the German ambassador’s residence.

Earlier this year it claimed responsibility for a small blast outside the offices of a commercial bank, and in late 2016, for placing a bomb at the Labour Ministry in Athens found by police and defused.

Small-scale attacks on businesses, state buildings, police and politicians are frequent in Greece, which has a history of political violence.