A bomb exploded outside the main building of Greece’s Skai TV station at 2:30 am local time on Sunday.
There were no injuries or victims as an anonymous phone-call alerted authorities of the threat.
On its website, the station said windows were smashed from the first to the sixth floors.
“The material damage is big on almost all floors, with the biggest seen on the third and fourth floors, where employees’ offices are located,” it said. “The picture is disheartening. Suspended ceilings collapsed to the floor, glass windows broke to pieces.”
Footage from within the building showed windows blown out with glass strewn across offices.
There was no immediate claim of responsibility. Armed far-left and anarchist organizations have attacked news media outlets in the past.
“This was a strike against democracy. Thankfully, there was only material damage — it’s a relief that no one was hurt — following the swift action taken by the police,” Public Order Minister Olga Gerovasili said.
“We will reinforce our democracy. This incident should give pause to those who leave a path open to terrorism and fascism.”
She said the anti-terrorism police were leading the investigation. Dozens of police investigators wearing white coveralls collected evidence from the scene, much of which remained cordoned off.
Journalists presenting its morning show were broadcasting live outside the station.
Its police correspondent said the device was estimated to contain about 5 kg of explosive materials and placed in a narrow alleyway close to the building.
SKAI is one of Greece’s biggest TV stations. It is part of a media group which includes a radio station and is affiliated with Greece’s major daily newspaper, Kathimerini.