Riot police spray pepper gas toward people, who were holding national flags and poster of Turkey's founder Kemal Ataturk, as they march to the mausoleum of Ataturk to celebrate the Republic Day in Ankara, Turkey, Monday, Oct. 29 2012. Police on Monday used tear gas and water cannons to try to break up a demonstration by tens of thousands of pro-secular protesters, but the march to mark the founding of the Turkish republic went on in defiance of a government ban.(AP Photo/Burhan Ozbilici)
