Dozens of helmet-wearing officers, backed by soldiers and police on horseback, stood on a railway track near Roszke where tens of thousands of migrants have been making their way into the EU in recent weeks.

Ahead of tougher rules from the Budapest government that come into force on Tuesday, a record 7,437 entered Hungary from Serbia on Monday, beating the previous day's highest of 5,809.

Authorities are getting ready to close the remaining gap in the country's 110-mile long border fence by blocking the rail line with a train cargo container covered with barbed wire.

Some migrants were told to walk to an approved border crossing a mile away, while others were taken by bus to a temporary holding centre near Roszke and some were put on trains bound for Austria in an apparent attempt to clear the backlog. 

Hungary has deployed hundreds of extra policemen to its border with Serbia and refugees who cross the frontier illegally could be arrested and face imprisonment from Tuesday.

The Hungarian move follows the decision by other neighbouring countries to impose more border controls amid the influx of hundreds of thousands of refugees into the continent from the Middle East and Africa.

Many of the refugees, who have been fleeing war zones including Syria, have been heading west to Germany, which said it expected a million migrants to enter the country this year - 200,000 more than previous estimates.

Over the weekend, Germany tightened controls along its border with Austria creating traffic jams at major crossings.

Police say they will conduct rolling checkpoints on major roads coming from Austria in a search for asylum seekers, but will not check every vehicle and driver for passports.

On trains from Austria, German police were removing asylum seekers at the first German station they reached and placing them on buses bound for refugee housing nationwide.

Austria and Slovakia have also renewed checks on its borders due to the migration crisis.

Slovakia said 220 extra officers have been deployed at border crossings and along the border, and said it was coordinating with police forces in neighbouring Austria, Hungary and the Czech Republic.

The Czech Republic has boosted its presence along its border with Austria but has not reintroduced border checks yet.

The European Commission plans to distribute 160,000 refugees across 22 EU member states over the next two years - a policy several countries are opposed to.

EU nations have already agreed to relocate 32,000 from Italy and Greece, with each country receiving €6,000 per refugee it takes in.