A video shows the moment that a strong bomb detonated on the grounds of Skai television in Neo Faliro, at 2.40 a.m. on Monday morning, causing serious damage to the building though no injuries.
Staff evacuated the premises after anonymous callers phoned in warnings to other media at 2 a.m.
The explosive device had been placed in a backpack andleft on the sidewalk outside the premises of Skai which also houses the Kathimerini newspaper.
The force of the explosion blew out windows as high as the fifth floor of the building.
"They wanted to hurt democracy and possibly take human lives," Deputy Citizens' Protection Minister Katerina Papakosta said.
She was echoed by the president of the Athens Union of Journalists, ESIEA, Maria Antoniadou, who described the hit as "an attack on information, on democracy."