Croatian Police have started registering the first group of migrants who reached Serbia’s border with Croatia.
The migrants who found a new route into the European Union (EU) boarded buses which took them towards the town of Sid, after Hungary closed the border with Serbia, leaving thousands attempting to reach Germany, which is the final destination for many, stranded.
Croatia has said it will not “just allow people to move through”.
New border restrictions and a row over allocating migrants have shown bitter divisions in Europe over the crisis.
Hundreds of stranded migrants spent the night in the open and in makeshift tents close to the Serbian border with Hungary.
About 150 migrants crossed into Croatia from Serbia.
On Tuesday, Hungary declared a state of emergency in the area, with hundreds of army and police deployed to enforce new laws, making it an offence to breach a razor-wire border fence.
The laws also made it a criminal offence, punishable by prison or deportation, to damage the newly built four metre fence along Hungary’s 175km border with Serbia.