Countries tussle over migrant flow

Thousands of migrants have become stranded in the western Balkans as Croatia, Hungary and Slovenia tussle over the EU's escalating refugee crisis.

Chaos, rumour and proliferating border obstacles have braked thousands of desperate people on their trek to reach northern Europe and turn the page on war or poverty.

In the latest hurdle, Hungary said on Saturday it had completed a second frontier fence designed to keep illegal migrants out.

A 41-kilometre barbed-wire barrier along part of its frontier with fellow EU member Croatia "was finished overnight Friday", defence spokesman Attila Kovacs said in Budapest.

The remaining 330km of the border runs roughly along the Drava river, which is difficult to cross.

The new barrier adds to a barbed-wire fence that Hungary set down along its frontier with Serbia and backed with laws threatening illegal migrants with jail.

That move sparked fierce condemnation internationally and forced the migrant flow towards neighbouring Croatia.

Reversing an open-door policy, Croatia on Friday said it was swamped and redirected the migrants back to Hungary.

Thousands crossed from Croatia to Hungary before the final section of the fence was completed, Budapest said.

Croatian Foreign Minister Vesna Pusic on Friday said Zagreb and Budapest had agreed to allow "vulnerable migrants" to cross.

Prime Minister Zoran Milanovic said on Saturday the policy of redirection would continue.

"There has not been an agreement with Hungary," he said in a visit to Beli Manastir, near the Hungarian border.

"We have in some way compelled them to accept the refugees by sending them (to the border) and we will continue to do so."

On the Croatian border with Slovenia, another EU member, hundreds of migrants spent the night in the open at the Bregana crossing, state-run HRT television reported.

At Harmica, several dozen migrants faced off with a cordon of riot police on the frontier bridge, demanding that Slovenian police let them enter the country.

Late Friday, police used tear gas against several hundred migrants, some with children, who had sought to push through the police line.

The clash happened shortly after Slovenian Prime Minister Miro Cerar said the small country might consider creating "corridors" for refugees wanting to reach northern Europe if they continue arriving in large numbers.

Slovenia's ambassador to Germany, meanwhile told the Rheinische Post newspaper his country would accept "up to 10,000" refugees.

Slovenian police said on Saturday 1287 had arrived as of midnight Friday, of which 483 were from Afghanistan, 470 from Syria and 126 from Iraq.

With no let-up in the flow of people desperate to find shelter in Europe from war and misery, new figures showed the European Union received almost a quarter of a million asylum requests in the three months to June.