Egyptian protesters throw stones at riot police, unseen, during clashes near the U.S. embassy in Cairo, Egypt, Thursday, Sept. 13, 2012. Protesters clash with police near the U.S. Embassy in Cairo for the third day in a row. Egypt's Islamist President Mohammed Morsi vowed to protect foreign embassies in Cairo, where police were using tear gas to disperse protesters at the U.S. mission. (AP Photo/Khalil Hamra)

Photo by: Khalil Hamra

Egyptian protesters throw stones at riot police, unseen, during clashes near the U.S. embassy in Cairo, Egypt, Thursday, Sept. 13, 2012. Protesters clash with police near the U.S. Embassy in Cairo for the third day in a row. Egypt's Islamist President Mohammed Morsi vowed to protect foreign embassies in Cairo, where police were using tear gas to disperse protesters at the U.S. mission. (AP Photo/Khalil Hamra)