BBC — around four thousand refugees arrived in mainland Greece as the government prepares for talks on tackling the huge number of people reaching its shores.
Two ferries carrying more than 4,200 people travelled to Piraeus port at night after leaving Lesvos island.
The whole EU is struggling to deal with an unprecedented influx of refugees.
Hundreds of people, mostly from the Middle East, remain stranded outside a railway station in Hungary after police stopped them travelling through the EU.
The EU’s border control agency, Frontex, says 23,000 refugees arrived in Greece last week alone – an increase of 50% on the previous week.
More than 160,000 people have arrived in Greece so far this year – already surpassing last year’s total.
One ferry carrying 1,749 people travelling from Lesvos arrived in the port of Piraeus, near Athens, late on Tuesday.
Another, with close to 2,500 on board, arrived early on Wednesday.
Under an EU rule known as the Dublin Regulation, refugees should seek asylum in the first EU country they enter. But Italy and Greece – the main landing points – say they cannot cope with the numbers and many of the refugees head north.
The number of migrants entering Europe has reached record levels, with 107,500 arriving in July alone.
Germany expects to take in 800,000 migrants this year – four times last year’s total.
EU interior and justice ministers will meet in Brussels on 14 September to address the crisis.