A ferry carrying about 2,500 migrants who had arrived clandestinely on Greek islands from the nearby Turkish coast has docked in Greece's main port of Piraeus near Athens.

The ferry arriving Thursday was chartered by the government and served as a registration center on the eastern Aegean island of Kos this week.

It left Kos on Wednesday with 1,300 migrants and picked up hundreds more from the islands of Leros, Kalymnos and Lesbos before sailing overnight to Piraeus.

Greece this year has been overwhelmed by record numbers of migrants arriving on its eastern Aegean islands, with more than 160,000 landing so far. The vast majority do not want to stay in the financially troubled nation and head north through the Balkans toward more prosperous European countries like Germany.