Thousands of jubilant Syrian civilians returned Saturday to the ruined northern city of Manbij, a day after U.S.-backed fighters drove the last Islamic State extremists from their stronghold near the Turkish border. Video from Kurdistan 24 television showed scores of vehicles making their way through rubble-strewn streets. Then came crowds of men, women and children, returning on foot from the countryside, where they took refuge while fighters from the Syria Democratic Forces fought to liberate the once-tranquil city. The SDF has said Islamic State was using civilians as human shields.