Displaced Iraqi children sit inside a UNHCR tent at a temporary camp set up to shelter people fleeing violence in northern Iraq on June 17, 2014 in Aski kalak, 40 kilometers west of the Kurdish autonomous region's capital Arbil. Militants pushed a weeklong offensive that has overrun swathes of Iraq to within 60 kilometers (37 miles) of Baghdad, as the UN warned the country's very existence was under threat. [Photo/CFP]