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 authorised to talk to reporters.