Belgrade: A surge of migrants entered Macedonia at the weekend, with 10,000 crossing into the small Balkan country in 24 hours, police said on Monday.

The high influx came amid fears of a new human bottleneck on the western Balkan route as Slovenia allowed limited numbers to cross into its territory, causing delays further down the migrant trail.

The travellers, mostly fleeing conflict and poverty in the Middle East, Africa and Asia, are being redirected to Slovenia on their way to northern Europe, after Hungary closed off its Croatian border with razor wire on early Saturday.

Further down the route, police said 10,000 migrants crossed from Greece and registered in Macedonia in the 24 hours to 6:00pm (1600 GMT) on Sunday.

Humanitarian workers in the field told AFP that the influx of people from Greece continued to be high until around midnight, when the numbers started to decline.

Police figures were not yet available for Sunday evening onwards.

From the Greece-Macedonia border, the main migrant route now goes up through Macedonia to Serbia, then through Croatia, Slovenia and Austria to Germany — the preferred destination for many.

But Slovenian authorities said on Monday they had refused to let in more than 1,000 migrants arriving from Croatia after a daily quota had been reached.