Blocked at the border

A migrant girl holds her toys as Macedonian policemen block migrants at the Greek-Macedonian borders, near the village of Idomeni, Greece November 20, 2015. Balkan countries have begun filtering the flow of migrants to Europe, granting passage to those fleeing conflict in the Middle East and Afghanistan but turning back others from Africa and Asia, the United Nations and Reuters witnesses said. REUTERS/Alexandros Avramidis

Migrants hold banners as they wait to cross the border from Greece to Gevgelija, Macedonia November 20, 2015. REUTERS/Ognen Teofilovski

A migrant carries his passport and belongings as he crosses the border from Greece in Gevgelija, Macedonia November 20, 2015. REUTERS/Ognen Teofilovski

Migrants hold their documents as they are blocked by Macedonian policemen at the border with Greece near Gevgelija, Macedonia November 20, 2015. REUTERS/Ognen Teofilovski

Migrants wait on the Greek side of the border with Macedonia as a Macedonian policeman stands guard on the Macedonian side, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

Migrants hold their documents as they are blocked by Macedonian policemen at the border with Greece near Gevgelija, Macedonia November 20, 2015. REUTERS/Ognen Teofilovski

Migrants hold banners as Macedonian policeman stands guard at the border with Greece near Gevgelija, Macedonia November 20, 2015. REUTERS/Ognen Teofilovski

Migrants are blocked by Macedonian policemen at the border with Greece near Gevgelija, Macedonia November 20, 2015. REUTERS/Ognen Teofilovski

A migrant speaks on his mobile phone while waiting on the Greek side of the border with Macedonia as a Macedonian policeman stands guard on the Macedonian side, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

An Iranian migrant is escorted back to Greece by Macedonian policemen after he tried to cross Greece's border with Macedonia illegally, near the Macedonian town of Gevgelija, November 19, 2015. REUTERS/Alexandros Avramidis

A migrant covers her face with a medical mask as she waits next to Greece's border with Macedonia, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

Migrants sit on the Greek side of the border with Macedonia as Macedonian policemen stand guard near the Macedonian town of Gevgelija, November 19, 2015. REUTERS/Alexandros Avramidis

Migrants (foreground) wait on the Greek side of the border with Macedonia as Macedonian policemen stand guard on the Macedonian side, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

Macedonian policemen detain an Iranian migrant who tried to cross Greece's border with Macedonia illegally, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

Migrants wait next to Greece's border with Macedonia, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

A migrant talks with a Macedonian policeman as he and other migrants wait to cross Greece's border with Macedonia near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

A migrant is escorted back to Greece by Macedonian policemen after he tried to cross Greece's border with Macedonia illegally, near the Macedonian town of Gevgelija, November 19, 2015. REUTERS/Alexandros Avramidis

Migrants wait next to Greece's border with Macedonia, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

A Macedonian policeman shouts as he guards the Macedonian side of the border with Greece, near the Macedonian town of Gevgelija, November 19, 2015. REUTERS/Alexandros Avramidis

Migrants wait next to Greece's border with Macedonia, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis

A migrant covered with a blanket walks near Greece's border with Macedonia, near the Greek village of Idomeni, November 19, 2015. REUTERS/Alexandros Avramidis