Twenty-six Egyptian soldiers were killed or wounded in attacks on several checkpoints in Sinai that included car bombings.
The military said it killed 40 assailants as it clashed with extremists in North Sinai.
The officials said the blitz attack started when a suicide car bomber rammed his vehicle into a checkpoint at a military compound in the southern Rafah village of El-Barth, followed by heavy gunfire from dozens of masked militants on foot.
The dead included a high ranking Special Forces officer, Col. Ahmed el-Mansi, and at least 20 others were wounded in the attack.
No group immediately claimed responsibility for the attack.