Refugees camp on a field as lightning strikes during a storm at the Greek-Macedonian border, near the village of Idomeni, August 21, 2015. Macedonian police fired tear gas and stun grenades to drive migrants and refugees back from its southern border from Greece on Friday but crowds continued to build up at a new bottleneck in an increasingly desperate flight to western Europe. At least 10 people were hurt in the brief flare-up, a day after the impoverished Balkan country declared a state of emergency on its border to halt a daily influx of up to 2,000 Syrians, Afghans, Iraqis and others heading north. REUTERS/Yannis Behrakis TPX IMAGES OF THE DAY