Egyptian forces have killed 30 extremists during several days of security operations in the Sinai Peninsula involving the army, air force and police, the military said on Saturday.
Cairo is battling an insurgency by ISIL's Egyptian affiliate in North Sinai that has killed hundreds of members of the security forces.
The military did not specify to which group the 30 extremists belonged but described them as "extremely dangerous".
Five others were arrested as Egyptian forces imposed a "tight siege" on the North Sinai provincial capital, El Arish, and the cities of Sheikh Zuweid and Rafah, the military said.
Egypt has struggled to quash attacks led by ISIL since the army ousted Islamist president Mohammed Morsi in 2013.
The ISIL bombing by of a Russian airliner carrying holidaymakers from a South Sinai resort in 2015 killed all 224 people on board and severely damaged the country's tourism sector.