FILE – In this Monday, June 29, 2015, file photo, an Egyptian policeman stands guard at the site of a bombing that killed Egypt’s top prosecutor, Hisham Barakat, in Cairo, Egypt. When Abdel-Fattah el-Sissi led the army’s overthrow of Egypt’s Islamist president two years ago, he promised to usher in new stability for the country. Instead, now President el-Sissi is facing an even tougher challenge: An Islamic militant insurgency that unleashed its worst violence yet the past week. (AP Photo/Eman Helal, File)