Roughly 10,700 migrants walked into Austria from Hungarytoday, more than arrived during all of yesterday, and a motorway passing through the border was partially closed, police spokesmen said.

Faced with growing crowds on its territory after Hungary barricaded its border with Serbia against migrants heading north, Croatia has been bringing people to its border with Hungary, which has been shuttling them to reception centres near Austria's eastern flank.

Roughly 10,700 migrants had arrived since midnight, a spokesman for the police in the eastern province of Burgenland said. Saturday's total was roughly 10,500.

Almost all of those arrivals were at the town of Nickelsdorf, which has generally been the main crossing point for migrants coming from Hungary.

Another police spokesman said Vienna-bound lanes on the A4 motorway, which goes through the border near Nickelsdorf, were closed, without elaborating.

The police have previously closed lanes of that motorway because of migrants spilling onto the road or setting off for Vienna on foot. A spokesman for ASFINAG, the company that operates the A4, was not immediately available for comment.

In Styria, a southeastern province that borders Slovenia, 1,000 migrants had entered the country on Saturday and Sunday combined, a spokesman for the police in that province said.