Around 6,000 suspected illegal immigrants have been arrested during a huge sweep in Athens.
Police said they will deport more than 1,600 of them to their home countries.
Those arrested and awaiting deportation have been sent to temporary holding centres. The rest were freed. Some 4,500 police took part in the weekend roundups.
Greece is Europe’s main entry point for illegal immigrants from Asia and Africa, who are seeking a better life in the West.
Some 100,000 are estimated to slip into Greece every year, mostly from neighbouring Turkey, and the influx has coincided with a rise in crime.