ATHENS, Greece (AP) — Human rights group Amnesty International is calling on Greek authorities to stop mass roundups of suspected illegal immigrants, arguing that police are treating law-abiding foreigners like criminals and subjecting thousands of detained persons to "degrading and inhumane" conditions.

The London-based group said Wednesday that legitimate asylum seekers were being denied proper assistance and that police were stopping and detaining suspects based on skin color.

Greek police launched the mass deportation drive — named operation Xenios-Zeus— over the weekend.

Some 2,000 officers in greater Athens detained around 7,000 immigrants. About 2,000 immigrants were eventually arrested on allegations of residing in Greece illegally.

Greece is the busiest transit point for illegal immigrants trying to reach the European Union.