Gunmen killed at least 15 Egyptian policemen at the border between Egypt and Israel.
Some of the seven wounded arrived at a crowded hospital.
Egypt's President Mohamed Mursi spoke on television after an emergency meeting.
(SOUNDBITE) (Arabic) EGYPTIAN PRESIDENT MOHAMED MURSI, SAYING:
"This incident will not pass lightly. The armed forces will assume complete control over these areas of Sinai, to secure them, and those who carried out the attack will pay a high price."
The gunmen also seized two military vehicles, which Israel's aircraft fired at.
A video distributed later by the Israeli army spokesperson unit was said to show one of the vehicles burning.
Sophia Soo, Reuters.
