Croatia closed seven of its eight border crossings with Serbia Thursday at midnight due to a huge influx of refugees and migrants.
However, refugees kept marching through the cornfields into Croatia on Friday morning.
The closure came after more than 11,000 refugees entered Croatia in just one day.
Authorities did not provide information on how long the closure will last.
The border crossings between Serbia and Hungary have been closed since Monday midnight, while refugees began rerouting towards Croatia on Thursday.
Europe is going through its most severe refugee crisis since the second World War.
Up to 300,000 refugees have arrived and traveled through Europe from January to August this year.