German rail operator Deutsche Bahn said Tuesday it would suspend key services to and from Austria and Hungary until October 4, citing border controls introduced to manage a record migrant influx.

The route from Budapest via Salzburg, Austria to the southern German city of Munich has been taken by tens of thousands of refugees in recent weeks.

Crowded aboard buses and trains, thousands more migrants flooded into Austria on Sunday from countries unable or unwilling to cope with a desperate human tide fleeing war and poverty for a better life in western Europe.

Austrian police said more than 11,000 entered the country on Saturday, and another 4,700 arrived Sunday through the Nickelsdorf border post from Hungary.

Austrian Chancellor Werner Faymann and German Vice Chancellor Sigmar Gabriel on Saturday called for United Nations countries to contribute an extra five billion euros ($5.65 billion) in aid for refugees living in camps in Lebanon and Jordan.

"We have to help countries where the misery is so great that people are going on the road," Gabriel said, in reference to the tens of thousands of migrants -- many of them Syrian refugees -- who have headed to Europe in recent months.

Thousands of migrants sought their way through a chaotic maze of rumor and proliferating border controls in the western Balkans on Saturday.

In the latest chapter in the EU's escalating refugee crisis, Croatia, Hungary and Slovenia tussled over how to cope with a wave of refugees desperate to reach northern Europe.

U.N. Secretary-General Ban Ki-moon has praised Lebanon, Jordan and Turkey for taking in millions of refugees from the war in Syria, which is now in its fifth year.

“Lebanon is hosting Syrian refugees equal in number to 25 per cent of its population,” Ban told a news conference on Wednesday less than 10 days before world leaders gather at the U.N. Headquarters in New York for general debate of the 70th session of the General Assembly.

Hundreds of migrants who had massed at the main train station in the Austrian city of Salzburg left on foot Wednesday in the hope of reaching Germany, a city spokesman said.

One day after Salzburg warned that the station might have to close due to the large numbers of migrants, government spokesman Johannes Greifeneder said the situation had "relaxed".

Several dozen migrants entered Croatia from Serbia early Wednesday, the first to enter the EU country after Hungary sealed its borders to thousand of people entering every day, an AFP correspondent saw.

The group of mostly Syrian or Afghan men, women and children crossed the border -- which was marked by nothing more than a stone -- early Wednesday morning and were picked up by police as they walked across a field.

Honking cars with stressed drivers banked up for kilometers (miles) at an Austrian-German road crossing Monday, hours after Berlin reimposed border checks to control a massive refugee influx.

Two German police officers checked the identity papers of the steady stream of drivers and passengers on a bridge where the morning traffic bottle-necked into a single lane.

Austria and Slovakia announced they were reinstating border controls Monday, following a similar move by under-pressure Germany which said it could face up to one million migrant arrivals this year.

Berlin's shock move, which struck at the heart of the EU's passport-free Schengen zone, had an immediate knock-on effect and ramped up the pressure on interior ministers holding emergency talks in Brussels later Monday.

Austrian Chancellor Werner Faymann called Sunday for an emergency EU summit to resolve the migrant crisis, saying his country's admittance of thousands of refugees crossing from Hungary was just a "temporary" measure.

Migrants have been streaming into Austria from Hungary since Friday, after Hungary laid on buses and trains to take them to the border following days of confrontations with migrants who were barred by police from continuing their journey westwards.