Two ships carrying the latest arrivals docked at Athens Piraeus port after sailing from Lesbos, one of several Greek islands struggling to cope with the huge waves of people crossing the Mediterranean from Turkey in flimsy boats.
Some 1,800 people arrived on the Greek mainland on Tuesday evening, with another 2,500 landing at dawn, port police said, adding that they had been taken to a nearby train station.
The ships were chartered by the Greek government to help relieve pressure on Lesbos, whose authorities and infrastructure are ill-equipped to deal with the huge influx of people.
More than 160,000 people have arrived in Greece this year, most of them fleeing war in the Middle East, as Europe grapples with its biggest migration crisis since World War II.
For many, Athens will be merely the first stop in a gruelling land journey north through the Balkans in a bid to reach Hungary, a key entry point into Europe, AFP reported.
The numbers crossing from Turkey to Greece have soared over the summer as the migrants, many paying over $1,000 to smugglers for the risky passage, take advantage of the calm seas to make the crossing.
The Greek government -- which has just accepted a third international bailout as it struggles to pay enormous debts -- has repeatedly said it is unable to cope with the scale of the influx, calling for a coordinated European response and for more resources to help it tackle the crisis.
Greek ministers were set to meet Wednesday morning on the crisis, which is likely to be at the centre of talks scheduled Thursday in Athens between Greek officials, the European Commissions vice-president Frans Timmermans, and Dimitris Avramopoulos, the EUs Migration and Home Affairs Commissioner.