At least six Egyptian soldiers and 24 attackers have been killed in a series of assaults on security posts in northern Sinai, according to security and hospital officials.
Dozens of fighters on Sunday used heavy machine guns and mortars to carry out a series of near-simultaneous attacks at and around the town of Sheikh Zweid.
Apache helicopter gunships were called in to repel the attackers, the officials, who spoke on condition of anonymity because they were not authorised to speak to the media, told The Associated Press news agency.
An army statement said 24 attackers were killed and one was wounded, while two of the fighters' SUVs were destroyed.
"Our security forces continued to sweep the area, confirming their continued efforts to eliminate terrorist elements," said the statement posted on the army's official Facebook page.
Security and medical sources told Reuters news agency that about 20 members of the security forces had been wounded in the attacks.
AP put the number of soldiers killed at seven and those wounded at 37, citing security and hospital officials.
The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) armed group claimed responsibility for the attacks.
Fighters linked to the group have staged dozens of attacks in the area in recent years.
On Friday, ISIL claimed an assault on security forces in the peninsula that killed at least six soldiers.