The Islamic State, fighting to redraw the map of the Middle East, has been coaching Egypt's most dangerous militant group, complicating efforts to stabilize the biggest Arab nation.
Confirmation that the Islamic Sate, currently the most successful of the region's jihadi groups, is extending its influence to Egypt will sound alarm bells in Cairo, where the authorities are already facing a security challenge from home-grown militants.
A senior commander from the Sinai-based Ansar Bayt al-Maqdis, which has killed hundreds of members of the Egyptian security forces over the last year, said the Islamic State has provided instructions on how to operate more effectively.
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