Several hundreds of migrants camp at the far end of a platform A at Vienna's train station (Westbahnhof) in Vienna on September 13, 2015. (AFP Photo)
A record 5,809 migrants entered Hungary in a new surge on Sunday, smashing the previous day's record of 4,330, Hungarian police said Monday.
The sharp increase came ahead of harsh new Hungarian laws coming into force Tuesday under which people entering the EU country illegally can be jailed.
Hungarian news website Index.hu reported that its neighbour Serbia would try to "push through" as many as 25-30,000 migrants on Monday before the new Hungarian laws bite.
Index quoted Hungarian official sources as saying Serbia would speed up the provision of buses for the migrants, who enter Serbia from Macedonia after leaving Greece.
Once in Hungary, most migrants seek to travel onto western Europe, particularly to Germany and Sweden, via Austria.
But with tens of thousands crossing its frontiers, German authorities on Sunday decided to reinstate border controls, and all trains between Austria and Germany were temporarily suspended, leaving thousands effectively stranded in Austria.
In addition to the new laws, Hungary is also building a controversial four-metre high (13-feet) fence all along its 175-kilometre (110-mile) border with Serbia.