Greek police evacuated about 50 migrants from a squat in the central Athenian district of Exarchia during a raid early Monday morning, state-run news agency ANA-MPA reported.
According to information cited by the agency, the migrants are mainly from Syria and Congo and included more than 10 children.
The building on 58 Themistokleous Street had functioned as a squat since 216.
Commenting a day after a government minister called for tough charges against anarchists evicted from squats in Koukaki over the weekend, the head of the Athens prosecutor's office, Evangelos Ioannidis, said that the evidence submitted to judicial officials by police justified misdemeanor charges, not felonies.
In the wake of the controversy that followed a police operation to empty two squats in Koukaki over the weekend, State Minister Giorgos Gerapetritis said on Monday that evicted squatters who hurled blocks of concrete and other projectiles at officers should face felony rather than misdemeanor charges.
A police operation was underway on Saturday to remove anarchists from two recently evacuated squats in the district of Koukaki in central Athens.
The buildings on 45 Matrozou and 21 Panetolikou Streets had been cleared by riot police in a sweeping operation on December 18 last year, but anarchists returned on Saturday afternoon, according to media reports.
Self-styled anarchists on Monday occupied the Greek Consulate in Berlin to express solidarity with squatters in Athens where police have in recent weeks been cracking down on occupied buildings.
A group of around 15 people occupied the office, hanging a black banner out of the windows reading "Solidarity with the squats" alongside the anarchist symbol.
The events that transpired during a riot police raid in the district of Koukaki on Wednesday morning to clear a squat were further blurred on Thursday after people claiming to be the occupants of the building targeted said the family members who were eventually arrested had nothing to do with their squat.
Police officers are seen entering an occupied building in the Athens neighborhood of Koukaki, one of three squats cleared early on Sunday. Nine people - seven Greeks and two foreign nationals - were arrested. Among those detained were two men and their father who were in a building that the police entered to gain access to one of the squats and who allegedly attempted to stop the officers.