Hundreds of angry migrants demonstrated outside Budapest's Eastern Railway Terminus on Tuesday demanding they be allowed to travel on to Germany, as the biggest ever influx of migrants into the European Union left its asylum policies in tatters.

Around 1,000 people waved tickets, clapping, booing and shouting "Germany! Germany!" outside the station. Later they sat down, staring at a police blockade erected at the entrance.

"Please, we are human too," said a sign in German held up by a young boy in a smaller group which protested into the evening.

A refugee crisis rivaling the Balkan wars of the 1990s as Europe's worst since World War Two has polarized and confounded the European Union, which has no mechanism to cope with the arrival of hundreds of thousands of poor and desperate people.

Germany is likely to accept by far the largest share. In the case of those fleeing the Syrian civil war it has effectively suspended an EU rule that asylum seekers must apply in the first EU country they reach.

But with trainloads of migrants rolling into Munich and Rosenheim from Austria and Hungary, it insisted on Tuesday that the rule was nevertheless still in force and urged other EU countries to abide by it.

The vast majority of refugees fleeing violence and other migrants escaping poverty arrive on Europe's southern and eastern edges but are determined to press on and seek asylum in richer countries further north and west. That means illegally crossing a bloc with no internal border controls to stop them.

Hungary has emerged as one of the main flashpoints of the crisis as the primary gateway for migrants traveling over land through the Balkans and into the EU.

Officials shut the Budapest train station altogether on Tuesday, then reopened it but barred entry to migrants. The decision was a reversal from Monday, when Hungary and Austria let trainloads of undocumented migrants head for Germany.

Government spokesman Zoltan Kovacs said the closure was an attempt to enforce EU law. The presence of about 2,000 people camped out in 40 degree-Celsius (104-Fahrenheit) heat in the square next to the station showed how hard that would be.

"We are thousands here, where should we go?" said Marah, a 20 year-old woman from Aleppo, Syria, who said her family had bought tickets for a Vienna-bound train.

European laws, known as the "Dublin rules", require asylum seekers to apply in the country where they enter the EU and stay there until their applications are processed, even though 26 members of the bloc have no border controls between them.

The countries where most first enter the European Union - Italy, Greece and Hungary - say they have no capacity to process applications on such a scale.

Germany announced last month it would allow Syrians arriving from elsewhere in the EU to apply for asylum without being sent back to the country where they entered the bloc.

"The decision, driven by practical considerations ... not, in most cases, to enforce the sending back of Syrian asylum seekers to other EU member states underlines the humanitarian responsibility of Germany for these particularly hard hit refugees," a German Interior Ministry Spokesman said.

"Germany has not suspended Dublin. Dublin rules are still valid and we expect European member states to stick to them."

WHERE SHOULD WE GO?

European leaders want the 28-member EU to do more to organize the unprecedented influx.

"For those refugees who are being persecuted or have fled war, there should be a fair distribution in Europe based on the economic strength, productivity and size of each country," German Chancellor Angela Merkel told a joint news conference in Berlin with Spanish Prime Minister Mariano Rajoy.

She and Rajoy both said the bloc's executive European Commission should draw up a list of safe countries, making it easier to send home migrants who were not genuine refugees.

The EU executive will outline new plans next week to share out refugees across European states and speed the deportation of unwanted migrants, the bloc's migration commissioner said.

"Some countries that were a bit reluctant ... have changed their mind because now they realize that this problem is not the problem of other countries but theirs as well," Dimitris Avramopoulos told Reuters.

Thousands of migrants have drowned this year trying to reach Europe across the Mediterranean in rickety vessels, while the peril of the overland journey was hammered home when 71 dead bodies were found in an abandoned truck in Austrialast week.

Austrian police said on Tuesday they had freed 24 teenagers from Afghanistan from a van in Vienna which had been welded shut, and arrested the Romanian driver. "It was like a rolling prison cell..they were crammed in, sitting and standing on top of each other," said Thomas Keiblinger, spokesman for the police in Vienna. "They would not have made it too much further."

Political parties that oppose immigration have gained ground across Europe, not least in Hungary where the government has reinforced the border with a razor wire fence and deployed thousands of extra police. More than 140,000 people have crossed into Hungary from Serbia this year alone.

Antal Rogan, the parliament caucus leader of Prime Minister Viktor Orban's ruling center-right Fidesz party, said on Tuesday "the very existence of Christian Europe" was under threat.

"Would we like our grandchildren to grow up in a United European Caliphate? My answer to that is no," Rogan told the pro-government daily Magyar Idok.

German Labor Minister Andrea Nahles said the influx of refugees and migrants would mean an extra 240,000-460,000 people would be entitled to German social benefits next year, costing the state an extra 3.3 billion euros ($3.7 billion).

Bavarian state minister for labor and social affairs, Emilia Mueller, said her state had been quick to set up an arrival and deportation centre for migrants from the Balkans unlikely to get refugee status but could not cope alone.

"We have a system in Europe which no longer works and Hungary is making this very clear."