Hungary’s government has declared a state of emergency at the Serbian border as tough new laws to stop refugees entering illegally took effect at midnight.
Hungarian police said they had arrested 60 people accused of trying to breach a razor-wire fence on the border with Serbia.
The state of emergency gives police extra powers and would allow troop deployments if parliament approves.
The EU states are facing a huge influx of refugees, many fleeing conflict and poverty in countries including Syria.
German Chancellor Angela Merkel told a news conference that “this problem can only be solved together. It is a responsibility for the entire European Union”.
The EU’s border agency said more than 500,000 refugees had arrived at the EU’s borders in 2015, compared with 280,000 in 2014. The vast majority have come by boat across the Mediterranean.
A boat following the most popular recent route, between Turkey and Greece, sank on September 15 leaving 22 people dead, Turkish media reported.
Starting on September 15, the European Union has agreed to relocate 40,000 migrants from Greece and Italy to other EU states. However, it has yet to agree on mandatory quotas for a further 120,000 asylum seekers.
After the new Hungarian laws came into effect at midnight, police sealed a railway crossing point that had been used by tens of thousands of migrants.
Around midday there were tense scenes as hundreds streamed towards the fence, some searching for a way through and others starting a sit-down strike, throwing down food and water in protest at not being granted passage.
Hungarian authorities said more than 9,000 – a new record – crossed into the country before the border was closed on September 14. Some 20,000 crossed into Austria.
From September 15, anyone who crosses the border illegally will face criminal charges, and 30 judges have been put on standby to try offenders.
The laws also make it a criminal offence – punishable by prison or deportation – to damage the newly-built 13ft fence along Hungary’s 110 mile border with Serbia.