Security officials say it is the first time that the army has fired missiles in Sinai since Egypt's 1973 war with Israel, which was an attempt to recapture the Sinai Peninsula.
Security officials tell The Associated Press that they launched the missile attack just hours after three security checkpoints were attacked by suspected Islamic militants in North Sinai's main city of El-Arish, some 50 kilometers (31 miles) from the Gaza-Israel border.
Officials say six people were wounded in the attacks -- among them a military officer, two soldiers, two policemen and a civilian whose condition is critical.
Bedouin resident Abdel Rahman Abol Malkhous says he saw attack helicopters overhead firing missiles about 30 kilometers (18 1/2 miles) east of El-Arish in the area known as Sheikh Zuwayed near the Rafah border crossing with Gaza.
Security officials say the military also carried out separate attacks just outside Sheikh Zuwayed.
Security officials spoke to the AP on condition of anonymity because they were not authorized to speak to the media.
Sinai reverted to Egyptian control under Cairo's 1979 peace treaty with Egypt. Israeli forces withdrew from the peninsula in 1982.