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.
The Hellenic National Defense General Staff (GEETHA) on Wednesday released a series of videos showing surveillance exercises in border areas.
The videos show exercises aimed at turning back undocumented migrants trying to enter Greece, including footage recorded during the night, and exercises on shooting ranges.