Riot police units detained about 80 people after raiding a squat near central Athens on Wednesday morning.
The raid came after a group of police officers guarding the building came under attack.
The building, known as Villa Amalia and situated on Acharnon Street, has been condemned and occupied by squatters for more than 20 years. Its ownership is being disputed by the City of Athens and the School Buildings Organization.
Meanwhile, a group of people raided the headquarters of the Democratic Left party located on nearby Aghiou Constantinou Street on Wednesday, acting in solidarity with the Villa Amalia squatters.
The latter were removed by riot police forces later in the day.