Thousands of migrants are arriving in mainland Greece as the government prepares for talks on tackling the huge number of people reaching its shores.

Two ships carrying more than 4,200 people travelled to Piraeus port at night after leaving Lesbos island as the whole EU reeks in the struggle to deal with an unprecedented influx of migrants.

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 migrants 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.

But in a reminder of the dangers they face, reports on Wednesday said at least 11 migrants, believed to be Syrians, were feared drowned after two boats sank as they left Turkey for the Greek island of Kos. The country's government says it lacks the resources to look after that many arrivals, but aid groups say authorities should be doing more.

On Tuesday, Greek President Prokopis Pavlopoulos called his French counterpart Francois Hollande and asked that the situation facing Greece be discussed at a senior European level. Greece's caretaker cabinet is set to convene later on Wednesday.

Many of those arriving in Greece resort to the island of Lesbos, where, according to the Kathimerini newspaper, 17, 500 migrants were registered in the last week.

One ferry carrying 1,749 migrants travelling from Lesbos arrived in the port of Piraeus, near Athens, late on Tuesday.

One of the passengers, a Syrian teacher named Isham, told our source: "You have to help us. We are human."

Another ferry, with close to 2,500 on board, was due to arrive early on Wednesday.