Police arrested two men on the weekend in connection with an attack on Friday by hooded members of an anarchist group on the offices of Proto Thema newspaper, which caused some damage to the building and two parked cars.
The group, Rouvikonas, claimed responsibility for the attack in a declaration posted on an anti-establishment website.
The two men, aged 32 and 37, were arrested after being stopped and searched on a street in the Athenian suburb of Nea Filadelfia.
Police said material evidence, including a full-face hood and gloves, as well as footage from CCTV cameras, linked them to the attack.
An Athens prosecutor on Saturday ordered the suspects released pending trial.