Sixteen militants were killed and 4 others arrested in a major crackdown launched by Egypt on Friday, the Egyptian army said in a statement carried by state TV early on Sunday.
Another 30 suspects were arrested, it said.
The Egyptian president Abdel Fattah al-Sisi on Nov. 29 ordered the military to defeat militants in North Sinai within three months, after
an attack on a mosque which killed more than 300 people, the deadliest such incident in the Arab world's most populous country.
A military spokesman said in an earlier statement that the operation would cover large parts of Sinai, but also parts of the Nile Delta and the Western Desert, where other militants have waged attacks, some believed to be staged out of neighbouring Libya.