German Chancellor Angela Merkel faced down far-right hecklers on Wednesday, vowing zero tolerance for "vile" anti-migrant violence as rescuers found 55 corpses on stricken boats in the Mediterranean.
The biggest migration crisis to hit Europe since World War II spiralled further as chaotic scenes erupted at a Hungarian border town with police firing tear gas, and Budapest considering deploying troops to stem a record influx of asylum-seekers.
Alarmed by the worsening situation, UN chief Ban Ki-moon urged countries "in Europe and elsewhere to prove their compassion and do much more to bring an end to the crisis".
The thousands of migrants and refugees who brave perilous journeys "should not, when they arrive, encounter new challenges," Ban said during a visit to Paris.
Hamstrung by a lack of a coherent European response to the crisis, governments have undertaken at times contradictory approaches to the problem.
Hungary is building a vast razor-wire barrier to keep migrants out, while Czech deputy prime minister Andrej Babis has called for the visa-free Schengen zone be closed with the help of NATO troops.
Meanwhile Germany, which is preparing to receive a record 800,000 asylum-seekers this year, has confirmed it has eased the asylum application procedure for Syrians fleeing the country`s brutal civil war.
But Berlin`s largesse has not been welcomed by everyone at home, particularly in the east where a spate of attacks has hit refugee centres.
On her visit to a migrant shelter in the eastern town of Heidenau, Merkel was greeted by about 200 protesters, some booing and shouting "traitor, traitor" and "we are the mob" as she arrived.
But the German leader vowed: "There will be no tolerance of those who question the dignity of other people."
She added that the more people who carry this message, "the stronger we will be and the better we will be able to address this task" of caring for refugees.
Public opinion was largely behind her, with 60 percent of Germans polled by public broadcaster ZDF saying that Europe`s biggest economy was capable of hosting the asylum-seekers.At least 55 dead bodies were discovered Wednesday on three overcrowded migrant boats in the Mediterranean, according to the Italian coastguard, on a day that saw some 3,000 others rescued in the sea.
Almost all of the victims were found in the hold of a boat found drifting off the Libyan coast by a Swedish vessel. Media reports said they had choked to death on gas fumes.
The macabre discoveries add to a toll of more than 2,300 people who have drowned in the Mediterranean since the beginning of 2015, already exceeding the death toll for the whole of 2014, according to the International Organisation for Migration.
In Hungary, another country overwhelmed by record numbers arriving, there were ugly scenes in the border town of Roszke as police fired tear gas at people who were trying to leave a refugee processing centre after refusing to be fingerprinted.
Hungarian lawmakers will vote next week on whether to send troops to stem the influx, as more than 2,500 people crossed into the EU country from its southern frontier with Serbia, days before the completion of the razor-wire fence.
Syrians, Afghans and Pakistanis, including more than 500 children, are among those rushing to reach Hungary before the border is sealed.
"We left because we were scared -- we had fear, bombs, war, killing, death," one Syrian man told AFP as he headed for the Hungarian border.
"That`s why we left Syria." UN refugee chief Antonio Guterres and French Interior Minister Bernard Cazeneuve called for the urgent creation of more so-called "hotspots" -- processing centres to sort refugees fleeing war from economic migrants who are simply in search of a better life.
As criticism mounted on the EU for its failure to reach a joint response to the crisis, Italy hit back at Germany and France over their claims that it is moving too slowly.
Merkel, at talks on Monday with French President Francois Hollande, warned that it would be intolerable if registration centres in Italy and Greece were not operational by the end of the year.
"Asking Greece and Italy to do their duty on immigration is like asking a country hit by floods to step up the production of umbrellas," Foreign Minister Paolo Gentiloni told the Corriere della Sera newspaper.
Leaders from the western Balkans -- the region that has become one of the main routes into the EU -- will attend a summit in Vienna on Thursday joined by Merkel, in a bid to work out a coherent approach to the crisis.