Those behind the "cowardly" attack on a border post with Israel Sunday in which gunmen killed 16 guards, will pay dearly, said a statement from the office of Egyptian President Mohamed Morsi.
"President Morsi says that this cowardly attack will not go without a response ... and that those who committed this crime will pay it dearly," said the statement, carried by the official MENA news agency.
Morsi held an emergency meeting with military and security officials after the attack, his spokesman Yasser Ali said.
Gunmen killed the 16 guards near the border with Israel, according to an updated toll given by the health ministry, before stealing two armoured vehicles and crossing into the Jewish state with one of them near the Kerem Shalom checkpoint.
In Israel, military spokeswoman Lieutenant Colonel Avital Leibovich told reporters one of the vehicles exploded by itself and the other was destroyed from the air.
The security situation in the Sinai has worsened in the wake of the uprising that forced president Hosni Mubarak to resign in February 2011.
Under the 1979 peace agreement between Egypt and Israel the number of Egyptian armed forces in the area has also been cut substantially.