A former Egyptian army officer who became one of the country's most wanted militants has called on fellow Egyptians to wage holy war against President Abdel-Fattah el-Sissi, describing him as a "new pharaoh."

The call purportedly by the militant, Hisham el-Ashmawi, came in an audio message reported Tuesday by SITE Intelligence Group, which tracks militant messages.

El-Ashmawi, who officials say is working closely with Sinai-based Ansar Beit al-Maqdis militant group that pledged allegiance to the Islamic State last year, is implicated in a several deadly attacks, including this month's bombing outside the Italian Consulate in Cairo.

The officials spoke on condition of anonymity because they are not authorized to talk to reporters.

Egyptian security officials say el-Ashmawi was dismissed from the special forces in 2009 for espousing radical ideas.