On Saturday, the military said its forces killed 27 suspected militants as part of the security operation that began on February 9.
Eight Egyptian soldiers and 14 militants were killed in fighting in central Sinai on Saturday when gunmen carrying explosive belts and grenades targeted a military checkpoint, the army said.
Security forces also arrested 114 suspects and found and destroyed a training camp which included a shooting range, an obstacle course and an underground conference room, it said.
The local affiliate of the Islamic State group branch has waged attacks against security forces and in the past year intensified its fight against Coptic Christians and other civilian targets.
Egypt has extended an ongoing nationwide state of emergency another three months, starting Saturday 14 April, the official gazette reported late on Friday.
A month earlier, the Interior Ministry announced that 16 security officers were killed during clashes with militants in Wahat in the Western Desert; the clashes also led to the killing of 15 militants.
The decree to extend the state of emergency, which was signed by Prime Minister Sherif Ismail, says that the extension is to "allow the Armed Forces and police to undertake necessary measures to face the dangers of terrorism and its funding, safeguard security nationwide, secure private and public property, and protect the lives of citizens".
El-Sissi first imposed a countrywide state of emergency in April 2017 after IS militants carried out two church bombings on Palm Sunday, killing at least 45 people.
Egyptian President Abdel Fattah al-Sisi issued a decree on Saturday to extend a curfew already in place in a new declaration.