Harrowing pictures of a drowned Syrian boy washed up on a Turkish beach brought home the horror of the escalating refugee crisis Thursday as Europe was accused of letting the Mediterranean become a "cemetery" for migrants.

Turkey's President Recep Tayyip Erdogan bluntly blamed EU states for the death of every single migrant who lost their lives making the perilous journey to Europe.

Hungarian police blocked hundreds of migrants from boarding trains to western Europe from Budapest's main rail station Tuesday, as figures showed more than 350,000 have risked their lives to cross the Mediterranean this year.

As hundreds of police, some in riot gear, moved people out of Keleti station, statistics from the International Organization for Migration (IOM) revealed the scale of the crisis in Europe which is facing the biggest movement of people since World War II.

The French prime minister was set to meet EU officials in the refugee pinch point of Calais on Monday as increasingly urgent efforts to deal with migration into Europe exposed divisions across the continent.

France is expecting several million euros more in aid from Brussels, a government source said, to help deal with the thousands of migrants and refugees camped out in "The Jungle" around the northern port, hoping to reach Britain.

The attitude of a number of eastern European countries towards the migrant crisis facing the EU is "scandalous", French Foreign Minister Laurent Fabius said Sunday, pointing in particular to an anti-migrant barrier in Hungary.

"When I see a certain number of European countries, particularly in the east, who do not accept quotas (of migrants), I find it scandalous," he told Europe 1 radio.

Hungarian police said Sunday that they have arrested a fifth man over the deaths of 71 migrants found in an abandoned truck in Austria last week.

Police are investigating a "Bulgarian national, a male, on suspicion of committing the crime of people smuggling," police said in a statement. The arrest was made late Saturday.

The European Commission on Tuesday said it stood ready to provide Hungary with emergency EU facilities as Budapest struggles to cope with the record numbers of migrants streaming across its borders.

"We are ready to create a hotspot in Hungary, because this country needs our support," said Natasha Bertaud, a spokeswoman for the commission, the EU's executive body which is tasked with coordinating the bloc's 28 member states in tackling the crisis.

The 100 or so refugees set off early evening, hoping that the short walk across Serbia's border into Hungary will be the last leg of their treacherous journey into the EU.

The group are mostly Syrians. Young and old, fathers carrying children on shoulders, mothers with toddlers. One man has a head wound, mugged he says by "Serbian mafia" the previous day.

Hungarian soldiers on Monday began erecting a controversial fence on the border with Serbia which is aimed at keeping out migrants.

"Works have begun on the construction of a section of the temporary border control fence," said a joint statement from the ministries of interior and defense.

The European Commission has pledged to send financial aid and experts to Hungary to help it cope with a surge in illegal immigration this year, a senior Brussels official said in Budapest Tuesday.

"Hungary will receive nearly eight million euros ($9 million) of support to help it cope with the migration issue," said Dimitris Avramopoulos, the commission's senior official for migration issues, told journalists after a meeting with Hungarian Foreign Minister Peter Szijjarto.

Austria on Wednesday blasted a decision by neighboring Hungary to suspend application of a key EU asylum rule as "unacceptable" and warned of "negative" consequences.

"Austria cannot tolerate that," Foreign Minister Sebastian Kurz told his Hungarian counterpart Peter Szijjarto in a telephone call, a day after Budapest announced it was opting out of a rule requiring a migrant's claim be processed in the EU country they first arrive in.