Article Photos: Mistrust runs deep over Egypt referendum 20/22

Egyptian riot police walk past a military tank guarding the presidential palace in Cairo, Egypt, Sunday, Dec. 16, 2012. Key Egyptian rights groups called Sunday for a repeat of the first round of the constitutional referendum, alleging the vote was marred by widespread violations. Islamists who back the disputed charter claimed they were in the lead with a majority of “yes” votes. (AP Photo/Hassan Ammar)