Families from Fallujah flee their homes during fighting between Iraqi security forces and Islamic State group during a military operation to regain control the city, , 40 miles (65 kilometers) west of Baghdad, Iraq, Wednesday, June 1, 2016. The U.N. children's fund has issued a stark warning to Iraqi troops and Islamic State militants in the battle for Fallujah to spare the children, the most vulnerable among tens of thousands of civilians trapped in the city west of Baghdad (AP Photo/Anmar Khalil)