The latest police sweep of undocumented immigrants in the capital led to 487 arrests, police said over the weekend.
Authorities said nine of the detainees were arrested because they were not in possession of the proper residence papers.
Officers said the sweep on Friday included a search of 14 properties, carried out as part of an ongoing crackdown, dubbed Xenios Zeus.
According to the police, some 44,734 migrants have been briefly detained since the start of the sweep operation.
Of these, 3,505 have been arrested.