Egyptian President Abdel Fattah al-Sisi publicly yesterday ordered his military chief of staff to restore security in Sinai within three months after militants killed more than 300 worshippers, demanding "complete brutal force."

Sisi made his remarks in a televised speech to mark the birthday of the Muslim Prophet Mohammed as the country reels from the Friday massacre in a North Sinai mosque.

The Islamic State (IS) group's Egypt affiliate based in the North Sinai is believed to have carried out the attack on the mosque associated with a mystical Sufi order.

"Allow me to take this opportunity to commit General Mohamed Farid Hegazy, in front of you and all the Egyptian people: you are responsible for restoring security and stability in Sinai within three months, you and the interior ministry," Sisi told the chief of staff in the audience.