Some 2,700 men, women and children entered Slovenian territory by trains and buses on Saturday, according to officials. Most of the migrants were from Syria, Iraq and Afghanistan, United Nations refugee agency spokeswoman Caroline van Buren said.
"They are fleeing from war... They are literally running for their lives," she told the AFP news agency at the border crossing of Petisovci.
Slovenian officials have established registration checkpoints in the border areas, as well as corridors to ship the migrants further north, toward Austria and Germany, where most of them intend to go.
Ljubljana also deployed the army to help the police "with logistics and equipment," Slovenian Prime Minister Miro Cerar said.
Detour to the west
The processing of migrants was running smoothly on Saturday, according to the UNHCR's van Buren.
"Unlike other countries, Slovenia had time to prepare... It's not perfect, but things are moving," she said.
Migrants were forced to take the long way to Austria after Hungary reinstated border controls with fellow EU member Slovenia earlier on Saturday. The move comes only hours after Budapest decided to block the migrants arriving from Croatia, in order to "protect" the citizens of Hungary and Europe, according to the Hungarian government.
Fears of a roadblock
The UN agency estimates that Slovenia has the capacity to accept around 7,000 migrants a day. At the same time, officials in the small Alpine nation claim they can only take 2,500 refugees a day, and that new groups would only be allowed in after previous groups leave the country.
However, Croatian police said that over 5,000 refugees entered the country since early Saturday, suggesting a possible backlog of migrants.
Blocking the path toward richer European countries could cause a domino effect in all the nations on the so-called Balkan route, including Croatia, Serbia, Macedonia and Greece.
Merkel heading to Turkey
Slovenia has stated it will continue taking refugees as long as Austria and Germany keep their borders open. Croatia also intends to keep the Serbian border open as long as newcomers can be shipped out to Slovenia.
"Slovenia will not close its border unless Germany closes its border. In that case Croatia will have to do the same…There is no alternative," Croatian Foreign Minister Vesna Pusic told state broadcaster HRT.
Thousands of migrants are arriving in Germany every day, stretching the country's capacity to provide shelter. While Germany can control its borders, it cannot close them completely, Chancellor Angela Merkel told the "Frankfurter Allgemeine Zeitung" newspaper.
"I am working with all my power for sustainable solutions, and they don't depend on us Germans alone and will take time," she said.
Merkel was set to travel to Istanbul on Sunday and press Turkey to crack down on people smugglers ferrying the migrants to European shores.
dj/bk (AFP, AP, Reuters, dpa)