Tensions reached boiling point today between European states worst affected by the migrant crisis as new figures showed no let-up in the influx of people fleeing war and poverty.
With migrant and refugee arrivals in Europe surpassing 110,000 in the first two months of the year alone, the United Nations warned that border restrictions being imposed by some states could cause chaos.
A diplomatic spat broke out between Greece and Austria, while Vienna lashed out at Germany's "contradictory" refugee policy.
The European Union voiced concerns about the risk of a "humanitarian crisis" particularly in Greece, which lies on the frontline of Europe's greatest migration challenge since World War II.
Thousands of people have been left stranded in Greece after Macedonia abruptly closed its border to Afghans, creating a fresh bottleneck on the Balkans route to northern Europe.
Athens also hit out at Vienna for failing to invite Greek representatives to a meeting on the crisis with ministers from western Balkan states on tomorrow.
Greek Prime Minister Alexis Tsipras called his Dutch counterpart Mark Rutte -- whose country holds the rotating EU presidency -- to complain after the foreign ministry blasted the Austrian meeting as "one-sided and not at all friendly" towards Athens.
Greece has accused Austria of undermining efforts to reach a joint European response to the crisis.
Austria retorted that it was a "fixed" meeting format and its summary would be available to EU interior and justice ministers when they meet on Thursday.
Austria lashed out at Germany's "contradictory" refugee policy after Berlin sharply criticised a daily limit introduced by Vienna on migrants registering and passing through the Alpine country.
"Germany should decide which number is acceptable to it," Austrian Chancellor Werner Faymann told reporters.
A statement added that he wished for a "respectful treatment of Austria's political decisions."
New figures published by the International Organization for Migration showed that 102,547 people had arrived in Greece and another 7,507 in Italy so far this year.
Another 413 lost their lives trying, including 321 who perished on the journey to Greece, the IOM said.
The Mediterranean was the scene of another tragedy today, with Italy saying it had found four bodies off the coast of Libya and rescued more than 700 migrants.
