No person was hurt but the explosion caused material damage to the building. The Tv channel writes on its website that the boxes were crushed on the first six floors.
Gaddafi is reported to have contained around five kilograms of explosives, and shall have been placed in a narrow alley next to the building.
Olga Gerovassili describes the explosion as an attack against democracy, but stresses that this is not threatened. Antiterroristpolisen has launched an investigation with a focus on Greek extremist groups.
Attacks against media companies, larger companies and embassies have been frequent in the country the last few years and is blamed on the anarchist and leading groups.