BAJAKOVO, Croatia (AP) — Shocked into action, Serbia and Croatia agreed Friday to increase the flow of asylum-seekers over their border after thousands were forced to spend a muddy night out in the open in near-freezing temperatures.

The two nations' interior ministers said they will start shipping migrants by train directly from Serbia to Croatia so they won't have to cross on foot, often trekking kilometers (miles) in the rain and cold weather.

"We have agreed to stop this torture," said Croatian Interior Minister Ranko Ostojic. "There will be no more rain and snow, they will go directly from camp to camp."

The surge is showing no signs of abating. The International Office for Migration says Greece over the last week experienced the largest single weekly influx of migrants this year, an average of 9,600 people per day compared to between 4,000 and 6,000 per day in September.

EU officials have called a summit for Sunday of several EU and Balkan leaders to focus on the migrant crisis.

Tensions have been building this week after the Balkan route into Western Europe shifted when Hungary decided to close its border with Serbia to migrants on Oct. 17. Refugees still cross from Turkey to Greece to Macedonia to Serbia, but now go via Croatia and Slovenia instead of Hungary, which has erected high, razor-wire fences along its borders with Serbia and Croatia.

In the future, refugees will register when they enter Serbia and will be able to cross into Croatia without any delays, which should speed up the process significantly, the ministers said.

Further west, thousands of migrants aiming to reach northern Europe walked out of refugee camps on the border between Slovenia and Austria on their own, frustrated after waiting long hours in overcrowded facilities.

Eager to move on, thousands spread out Friday along railway tracks, highways and mountain roads. Confused about what roads to take, some migrants later turned back and returned to the refugee camps to wait for buses to other locations.

Overwhelmed after more than 50,000 migrants crossed in just a week, tiny Slovenia said it has not ruled out erecting a fence of its own along parts of its 670-kilometer (400-mile) border with Croatia. Prime Minister Miro Cerar was quoted Friday as saying Slovenia will consider all options, if left on its own to cope with the influx of thousands of people.

"Our sights are foremost on finding a European solution," said Cerar. "But should we lose hope for this ... all options are open, within what is acceptable."

The country of 2 million people already has deployed 650 army troops to help the police manage the flow and has asked the European Commission for 60 million euros ($68 million) in aid, police gear and personnel.

Several EU nations have promised to send police officers to help Slovenia, which is so overloaded that a soccer match Saturday had to be cancelled because there were no officers available to guard it.

Slovenia and Croatia have traded barbs since the start of the crisis, with Slovenia accusing Croatia of dropping migrants uncontrollably at its doorstep.

Croatian police on Friday were seen escorting around 1,500 migrants close to an unmanned section of the country's border with Slovenia before letting them cross on foot. The group arrived on a train and was led by police to a small bridge to cross into Slovenia, where they will be taken to a collection center.

At the Serbian border, 5,000 people gathered around fires, under tents and wrapped in blankets as they waited all night to cross into Croatia. One elderly resident of the Croatian village of Kljuc Brdovecki said it was heart-breaking to see the refugees in those conditions.

"They are truly miserable. When I watched them walking past one night, I got up to watch, I watched and cried," Jela Karic told The Associated Press. "They walked this way, tired to the point of sleeping, in the middle of the night. When you watch them, all you can do is cry."

Serbian Interior Minister Nebojsa Stefanovic said his nation and Croatia will ask the EU to recognize the Serbian registration process — which includes finger and palm-printing and biometric passes — so refugees don't have to undergo the same procedure over and over again.

"With the winter coming, it is important to agree on a speedy flow of these people," Stefanovic said.


Ali Zerdin in Ljubljana, Slovenia, Sabina Niksic at the Croatia-Slovenia border, Ivana Bzganovic in Berkasovo, Serbia, Jovana Gec in Belgrade, Serbia, and Petr David Josek and Balint Szlanko at the Slovenia-Austria border have contributed.