Hundreds of migrants have broken through police lines on Hungary's border with Serbia and are walking towards the capital, Budapest.
The migrants had earlier broken out of a registration camp at Roszke.
About 300 are on a motorway, escorted by police. Some later reportedly agreed to be bussed to a reception centre.
Meanwhile, the Greek government and UN refugee agency brought in extra staff and ships to deal with some 25,000 migrants on the island of Lesbos.
The processing centre has been set up on an abandoned football ground to help the stranded migrants.
The hope is that the centre - which will operate for five days - will help people to buy tickets for specially chartered ships to get to Athens, the BBC's Jonny Dymond on Lesbos reports.
Local authorities have been overwhelmed by the migrants who have been forced to live in squalid conditions, our correspondent adds.
Athens has already requested emergency EU assistance to deal with migrants arriving from Turkey.
Earlier, German Chancellor Angela Merkel warned that the "breathtaking" flow of migrants into Germany would change the country in the coming years.
Hungary has become a flashpoint as thousands of migrants and refugees from the Middle East and Africa move north to claim asylum in Germany and other countries.
The country's defence minister, Csaba Hende, resigned on Monday, reportedly over problems with the construction of a border fence meant to keep migrants out.
In other developments:
- The UK will accept up to 20,000 refugees from Syria over the next five years, David Cameron has told MPs
- At least 150 migrants in southern Denmark have tried to march towards the border with Sweden, forcing police to close a motorway.
- The US administration "is actively considering a range of approaches to be more responsive to the global refugee crisis, including with regard to refugee resettlement", a White House spokesman has said.
Culled from BBC News
Hakuna maoni:
Chapisha Maoni