An Egyptian protester throws stones toward riot police next to a burning police car 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

An Egyptian protester throws stones toward riot police next to a burning police car 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)