Large groups of refugees and migrants in Hungary are trying to walk to the Austrian border, after defying official efforts to stop them.
Hungary has announced it will send buses to transport them to the border.
As darkness fell, police advised around 1,000 walkers on the main motorway to Vienna to put on light-coloured clothing so that they could be seen.
Earlier on Friday another group escaped along railway tracks in Bicske, to the west, from a train stopped by police.
European Union states are struggling to agree on how to deal with the crisis.
The Hungarian, Czech, Slovakian and Polish prime ministers have rejected quotas for EU nations.
In a statement the leaders rejected "any proposal leading to introduction of mandatory and permanent quota for solidarity measures".
The chaotic scenes in Hungary - a main transit country for those seeking to claim asylum in Germany and other countries in northern and western Europe - have continued for another day, as authorities struggle to deal with many thousands of people desperate to reach western Europe.
A group of around 1,000 who had been waiting days at Budapest's Keleti station grew frustrated with the lack of international trains, and decided to walk to Austria - a distance of 180km (110 miles).
Hungarian police seemed to be escorting but not stopping them.
The BBC's Matthew Price, walking with the migrants, says large numbers of people, some pushing wheelchairs and buggies, are walking down the hard shoulder of the main motorway from the Hungarian capital to Vienna.
Most of those he spoke to were from Iraq or Syria.
As night fell, many continued to walk, but others - including a family with five children - appeared to stop for the night on the hard shoulder, or in adjacent fields.
One man told the BBC he would continue to the Austrian border:
"Then to Vienna, then to Germany.
"We won't stop. Our target is to Germany, to our mum, to Merkel."
Meanwhile the stand-off between Hungarian police and hundreds of migrants, who refused to leave a train in Bicske for over 24 hours, has ended.
A large number of people escaped from the train on Friday afternoon and are walking along the train tracks heading west.
Those migrants who did not escape - many of them families with children - have been escorted onto buses to be taken to a transit camp.
A Pakistani man in his fifties collapsed and died after leaving the train.
Elsewhere in Hungary on Friday:
- There were clashes at Keleti station after far-right extremists threw two firecrackers towards migrants, sparking an angry response
- Hundreds of people have broken out of a refugee camp at Roszke near the Serbian border and are being pursued by police. Video from the camp showed clashes between migrants, trying to break out, and riot police, who used spray
- Hungarian MPs have approved tougher border controls and penalties for migrants trying to pass through to Germany
- More than 2,000 people have joined an Austrian Facebook campaign to organise a convoy to pick up migrants and take them out of Hungary - although the Austrian interior ministry warned that participants would be liable to prosecution
Under EU regulations, anyone wishing to seek asylum must do so in the first EU country they reach.
But many of those who have arrived in Hungary do not wish to be registered there because it is more likely to send migrants back, and has a relatively small population and economy.
They want to continue on to seek asylum in Germany and other richer countries.
Hungarian Prime Minister Viktor Orban warned on Friday of "the end of Europe".
"Today we are talking about tens of thousands but next year we will be talking about millions and this has no end," Mr Orban said.
Antonio Guterres, head of the UN refugee agency, the UNHCR, said the crisis was a defining moment for Europe.
In a statement, he said Europe needed to build "adequate reception capacities", especially in Greece, replacing a "piecemeal" approach with a "common strategy".
In other developments:
- The UK government - under pressure over its response to the crisis - has agreed to provide settlement for "thousands more" Syrian refugees and an extra £100m in aid for Syrians in the Middle East
- Members of the European Commission are in the Greek island of Kos to examine the difficulties caused by the large numbers of refugees and migrants landing there
- EU foreign ministers are meeting in Brussels
- Some 50 migrants are feared to have drowned after their boat sank off the coast of Libya, according to the International Organization for Migration
Migrant crisis: coverage in detail
Migrant crisis: Key questions
Why are so many people on the move?
EU countries are under pressure as a surge of migrants from the Middle East and Africa seek to escape war and oppression. Italy, Greece and Hungary, on the the EU's borders, are under particular pressure.
Where are they coming from?
Syrians make up the largest group by nationality, followed by Afghans and Eritreans.
Why are people fleeing Syria?
An uprising against President Bashar al-Assad erupted in March 2011, since when the country has since descended into a complex civil war. More than 240,000 people have been killed, and around half Syria's pre-war population have fled their homes.
Migrants or refugees?
The word migrant is defined in the Oxford English Dictionary as "one who moves, either temporarily or permanently, from one place, area, or country of residence to another".
A refugee is, according to the 1951 Refugee Convention, any person who "owing to a well-founded fear" of persecution is outside their country of nationality and "unable" or "unwilling" to seek the protection of that country. To gain the status, one has to go through the legal process of claiming asylum.
The word migrant has traditionally been considered a neutral term, but some criticise the BBC and other media for using a word they say implies something voluntary, and should not be applied to people fleeing danger.
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