Croatian border restrictions remain as Serbian deadline approaches

Croatia said on Wednesday it would lift border restrictions with Serbia only once Belgrade begins sending migrants to Hungary, standing firm against a midnight deadline when Serbia says it will retaliate.

Zagreb has banned all trucks but those carrying perishable goods from entering from fellow ex-Yugoslav republic Serbia and has shut seven of eight road border crossings, angry that its neighbor is sending tens of thousands of migrants across their joint border rather than to neighboring Hungary or Romania.

The dispute is fast becoming their most serious in the two decades since Croatia fought Belgrade-backed Serb rebels in a 1991-95 war to forge its independence from socialist Yugoslavia.

Serbia has set a midnight deadline for Croatia, a member of the European Union since 2013, to lift the blockade or face "political, legal and economic measures" in retaliation. It has not specified what the measures might contain.

Speaking in Brussels, where he was attending a summit of European Union leaders on the migration crisis, Croatian Prime Minister Zoran Milanovic told reporters:

"Until I see the Budapest-Belgrade axis stop burdening Croatia with refugees, I will remain convinced that they are doing something behind our back. I will remain so convinced until Serbia starts sending people to Hungary too, and not just to Croatia."

Croatian state radio had earlier reported that cars and trucks were flowing freely across the border after a group of truck drivers called off a protest, but it emerged cargo traffic was moving only in one direction.

More than 30,000 migrants, many of them Syrian refugees, have entered Croatia from Serbia since Tuesday last week, when Hungary barred their entry to the EU by sealing its southern border with Serbia with a metal fence.

They are being bussed by Serbia directly to the Croatian border, having entered Serbia from Macedonia, and trekking through fields beyond the official border crossings.

Croatia says it cannot cope with the numbers, saying Serbia should send them to Hungary through their main official border point at Horgos, and to Romania too.

Croatia is sending migrants north across its own border with Hungary, which in turn sends them to Austria, but is struggling to keep pace with the influx.

"We are still waiting for a single bus to go through Horgos," Croatian Interior Minister Ranko Ostojic told Reuters, when asked when the blockade might be lifted in full.

(Additional reporting by Zoran Radosavljevic in Zagreb and Matt Robinson and Ivana Sekularac in Belgrade; Editing by Tom Heneghan)