IDOMENI, Greece (AP) — Groups of frustrated migrants, including families with small children, walked along north-bound Greek highways Thursday hoping to reach Macedonia after authorities stopped their buses to ease a bottleneck on the practically blocked border.

It was yet another sign of Europe's failure to address its worst immigration crisis since the end of World War II. As some 2,000 migrants per day cross illegally into Greece on their way to a better life in the continent's wealthier north, restrictions imposed by Austria and Balkan nations have left thousands trapped in the financially broken country — which has seen nearly a million arrivals since January 2015.

The Greek government underlined its annoyance Thursday by recalling its ambassador to Austria for consultations — "in order to safeguard friendly relations" between the two states, said Foreign Minister Nikos Kotzias.

Greece does not detain people entering the country illegally if they are from Syria, Iraq and several other countries whose citizens are considered eligible for asylum.

Defense Minister Panos Kammenos said about 20,000 migrants are stuck in the country, and pledged to set up new camps near the Macedonian border within the next 10 days that could host them all in "decent" conditions.

"We want to at least ensure that these people are not on the highways, or out in the fields, that there are no children on the roads," he said.

Many of the migrants walking along highways Thursday gave up after a few kilometers (miles) and were moved on by police to the next stopping point on the route north — usually a gas-station parking lot. Others managed to find taxis to the Idomeni border crossing, where about 2,800 people were waiting, some for up to four days.

But Macedonian authorities only allowed about 100 people to enter on Thursday.

Nadica V'ckova, a spokeswoman for Macedonia's crisis management department, told the AP that the country was restricting the entry of migrants to match the number leaving the country.

Damascus pharmacist Wassim al Mousalli, 37, said he, his wife and children aged 3 and 6 spent two days camped by the Idomeni crossing.

"We spent the night in a small tent, the children were very cold," he said. "I want to reach Germany, and my main question is why are the borders being kept closed."

About 2,000 people arrived Thursday in ferries from the islands at Piraeus, the port of Athens, and nearly 800 more were expected by midnight, the Merchant Marine Ministry said. Normally, they would then take buses straight to Idomeni.

But authorities said 40 buses carrying 2,000 migrants were stopped at various points along the country's main 500-kilometer (310-mile) highway leading north from Athens, to ease the buildup at Idomeni. Traffic has also been slowed by tractor blockades by farmers protesting bailout measures.

"It took me 20 hours to get here. The police kept stopping us, but I couldn't wait," said 23-year-old Syrian university student Walaa Jbara, speaking near the border and clutching his smartphone.

"I'm checking the news on Facebook, and I know the Macedonians are not letting people through."

In Athens, two men hanged themselves from a tree in central Victoria Square, an informal staging point for refugees and economic migrants arriving from the Aegean Sea islands, where about 300 people were gathered Thursday. Police said the men, who were rushed to hospital, one unconscious, had tried to draw attention to their predicament.

Greece as well as international aid agencies have strongly criticized Austria and Balkan counties for the new transit rules.

"All it will do is exacerbate an already grave humanitarian crisis and put the most vulnerable at increased risk," said Kirk Day of the New York-based International Rescue Committee.