BELGRADE, Serbia -- Hundreds of migrants and asylum seekers set off on foot Friday toward Serbia's border with Hungary to protest its decision to keep its border closed for most people trying to reach the European Union. Migrants held cardboard placards saying "Hungary Open Borders" or "No Borders, No Fence" as they marched Friday in a long column along a road leading north from Belgrade toward the Hungarian border 120 miles away. Several police cars drove slowly by the marchers, who were carrying bags and blankets.