Egypt's Muslim Brotherhood said on its website that the attack on a police station in Sinai on Sunday in which 16 policemen were killed "can be attributed to Mossad" and was an attempt to thwart Islamist President Mohamed Morsi. Israel later denied the claim.
The statement said Mossad, the Israeli intelligence agency, was trying to abort the Egyptian uprising that toppled president Hosni Mubarak last year and that it was "imperative to review clauses" of the agreement between Egypt and Israel.
Israel on Monday dismissed the claim that it was in any way involved in the deadly attack.
"Even the person who says this when he looks at himself in the mirror does not believe the nonsense he is uttering," Foreign Ministry spokesman Yigal Palmor said.
Egypt branded the Islamist gunmen behind the attack as "infidels" and promised on Monday to launch a crackdown following the massacre that has strained Cairo's ties with both Israel and Palestinians.
The bloodshed represented an early diplomatic test for Mr. Morsi, who took office at the end of June after staunch U.S. ally Hosni Mubarak was overthrown last year in a popular uprising.
Mr. Mubarak had cooperated closely with Israel on security and suppressed Islamist movements such as Mr. Morsi's Muslim Brotherhood which rejects violence to achieve its goals but whose leaders often voiced hostility towards the Jewish state.
The group said on its website on Monday: "This crime can be attributed to the Mossad, which has been seeking to abort the revolution since its inception and the proof of this is that it gave instructions to its zionist citizens in Sinai to depart immediately a few days ago."
"(It) also draws our attention to the fact that our forces in Sinai are not enough to protect it and our borders, which makes it imperative to review clauses in the signed agreement between us and the zionist entity," the group said.