Macedonian police officers block stranded migrants trying to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





A Macedonian police officer shoots in the air as stranded migrants try to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants argue with Macedonian police officers as they try to cross the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants make their way through a forest as they try to cross the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants scuffle with Greek police officers as they try to cross the Greek-Macedonian border, near the village of Idomeni, Greece, December 2, 2015. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants run as tear gas fills the air during clashes with Macedonian police as they try to cross the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. Picture taken from Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





A stranded migrant argues with a Macedonian police officer as he tries to cross the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Macedonian police officers block stranded migrants trying to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





A Macedonian police officer hits a stranded migrant attempting to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Macedonian police officers block stranded migrants trying to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Macedonian police officers block stranded migrants as they attempt to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants scuffle with Greek police officers as they try to cross the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants walk next to the Greek-Macedonian border, in search of a cross point, near the village of Idomeni, Greece December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)





Stranded migrants try to storm the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. (Photo by Alexandros Avramidis/Reuters)





A stranded migrant boy plays with a ball at a makeshift camp next to the Greek-Macedonian border, near the village of Idomeni, Greece December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)