Two refugee men hanged themselves from a tree in central Victoria Square in Athens, an informal staging point for refugees 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.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.