Austria's chancellor Werner Faymann criticised Hungary for its handling of the refugee crisis yesterday, likening the country's policies to Nazi deportations during the Holocaust. In an escalating a war of words between the two countries, Hungary responded by summoning the the Austrian ambassador.

Thousands of refugees are crossing the border to Hungary, an eastern outpost of Europe's passport-free Schengen zone, every day, and many are travelling on to the continent's more prosperous west and north in what is Europe's worst refugee crisis since the Yugoslav wars of the 1990s. This weekend Germany said some 40,000 refugees could arrive in the country over the next two days. Yesterday 3,600 arrived at Munich's main train station during the morning as authorities warned they might not be able to cope with an extra 6,800 that could arrive by the evening. In a reminder of the perils refugees face Greek coastguard authorities said four children have gone missing after a dinghy carrying them and other refugees sank off the island of Samos yesterday.

The coastguard picked up 25 survivors early yesterday morning north east of the Aegean island. They told authorities that four minors were missing. Separate reports suggested the children were aged between three and 14. The authorities could not confirm the ages.

Meanwhile the spat between Austria and Hungary grew following an interview with German news magazine Der Spiegel, in which Austrian Chancellor Werner Faymann likened Hungarian Prime Minister Viktor Orban's treatment of refugees to the Nazis' deportations of Jews and others to concentration camps.

"Sticking refugees in trains and sending them somewhere completely different to where they think they're going reminds us of the darkest chapter of our continent's history," he said.

On Sept. 3, migrants boarded a train in Budapest in the belief that they were heading to the border with Austria but the train was stopped 22 miles west of the capital in the town of Bicske, where Hungary has a camp for asylum seekers.

Hungary dismissed Faymann's comments as "utterly unworthy of a 21st century European leader" and summoned Austria's ambassador.

Hungarian foreign minister Peter Szijjarto said the Austrian chancellor had been pursuing a "campaign of lies" against Hungary for weeks that made it harder to find a common European solution to the crisis.

Many refugees and migrants now arriving in Hungary want to avoid being registered there for fear of being returned to Hungary later as they travel on to richer countries in western and northern Europe.

Saeed, a 25-year-old Syrian, was one of many refugees complaining about his treatment in Hungary. Speaking to reporters euters in the Austrian border town of Nickelsdorf, he said he had spent the last six days in Hungary, where he was taken to five camps and had to sleep standing up in an overcrowded room.

"They put us in jails. We were there for a week, so little food, one of these little breads in the morning and one at night ... Everyone has a cold because there is no heating or anything there," he said.

"I escaped from Syria because I wasn't treated like a person, like a human being there and I came to Hungary and I was treated like an animal," he added.

On Friday, an online video emerged of crowds clamouring for food in a border camp as police in surgical masks tossed them packs of sandwiches. Police in Hungary said they had launched an investigation into the scenes.

Orban, a conservative populist always keen to undercut his main political rival, the far-right Jobbik party, has taken a tough stance during the crisis and told yesterday's edition of German newspaper Bild that refugees should be sent back once Hungary closes its borders on Sept 15.

Asked where, he said: "Where they came from. These migrants are not coming to us from war zones but rather from camps in countries neighbouring Syria like Lebanon, Jordan and Turkey. They were safe there."

He said he would take a refugee family into his own home if he was sure this would not encourage others to come to Europe, adding that the continent would "perish" if it continued to take in millions of refugees.