The Muslim Brotherhood's accusation on Monday that Israels Mossad was behind Sunday's terror attack on a checkpoint in Sinai is "nonsense" and even the accusers themselves do not believe what they are saying, Foreign Ministry spokesman Yigal Palmor said Monday.
Egypt's Muslim Brotherhood said on its website on Monday that the attack on Sunday, in which terrorists killed 16 Egyptian policemen and proceeded to breach the border with Israel, "can be attributed to Mossad" and was an attempt to harm the Egyptian revolution and topple Islamist President Mohammed Morsi.
Israel dismissed all allegations of involvement in the attack.
"Even the person who says this when he looks at himself in the mirror does not believe the nonsense he is uttering," Palmor said.
An Egyptian official said insurgents had crossed into Egypt from the Gaza Strip before attacking the border station on Sunday. They then stole two Egyptian vehicles and headed to nearby Israel, where they were eventually killed by Israeli fire.
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 Brotherhood said on its website: "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." The statement referred to a recent severe travel warning issued by the Israeli Counterterrorism Bureau immediately preceeding the attack.
"(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, referring to stipulations in the peace treaty between Israel and Egypt, signed in 1979, requiring the demilitarization of Sinai.
However, Egypt's military said the perpetrators behind the Sinai attack had the help of Palestinian militants, saying "forces from the Gaza Strip" aided them by shelling the Egyptian-Israeli border crossing with mortars as the attack was taking place.
An Egyptian government official charged anonymously that at least some of the attackers came from Gaza, infiltrating through smuggling tunnels under the border.
Hundreds of tunnels run under the 15-kilometer (9-mile) Gaza-Egypt border, dug over the years to evade border restrictions and move contraband, including weapons and militants.
Hamas announced it closed the tunnels temporarily following the attack. Egypt indicated it would crack down from its side after mostly ignoring the underground passages for years.
Meanwhile, dozens of demonstrators chanting "leave, leave" gathered in front of the residence of the Israeli ambassador in Cairo on Monday night to demand his deportation, the state newspaper Al-Ahram said.
“It’s definitely Israel who is behind it; we demand the termination of any diplomatic relations with Israel,” Al-Ahram quoted Ahmed El-Toni, a protester who referred to himself as an “independent activist," as saying.
Mohamed Bakhati, another protester at the demonstration told Ahram Online that an escalation in protests against the ambassador's house was not an option at the moment as the ambassador himself was not in Egypt.
"However, we’re giving a chance to President Morsi until after Ramadan; if retribution for those who died is not reached, we will go back to the streets,” he said.
Other protesters were heard chanting, "Oh Zionist, oh cowards, Egyptian blood is not cheap," and "retribution, retribution, they shot our sisters with bullets," and "get out, ambassador of swine," according to the Egyptian Al-Akhbar newspaper.
Egyptian security forces surrounded the ambassador's house to keep demonstrators from storming it, amid concerns of a repeat of incidents last year when the Israeli Embassy in Cairo was raided twice by anti-Israel protesters.
Foreign Minister Avigdor Lieberman told Israel Radio on Tuesday that the protests were not serious and did "not catch on." He called the protesters "radicals who are just trying to rouse the public."
Asked if Sunday's attack presents opportunities for Israel and Egypt to strengthen relations by cooperating in the hunt for the perpetrators, Leiberman said, "The ball is in Egypt's court. We offered them help with the investigations, we gave them the bodies of the terrorists, we told them we are at their service. We would be happy to help and provide information. But for now we are waiting."
The foreign minister also said that Egyptian security forces "already know that the perpetrators were al-Qaida-linked global jihadists operating in Sinai."
Asked whether more troops were needed in Sinai to maintain security there, Lieberman said "They have enough troops there; they just need to make a political decision to tale action, and to do so with determination."
The bloodshed on Sunday represented an early diplomatic test for Morsi, who took office at the end of June after staunch U.S. ally Hosni Mubarak was overthrown last year in a popular uprising.
Mubarak had cooperated closely with Israel on security and suppressed Islamist movements such as Morsi's Muslim Brotherhood which rejects the use of violence to achieve its goals but whose leaders often voiced hostility towards the Jewish state.
Echoing the Brotherhood's accusation against Mossad, Hezbollah Secretary-General Hassan Nasrallah also blamed Israel for Sunday's attack, saying on Monday night that the Jewish state was the greatest beneficiary of the incident.
In Washington, the U.S. State Department voiced scepticism over the involvement of the Mossad and urged Egypt to improve security in Sinai.
Asked if it was conceivable the Israeli intelligence service launched the attack, State Department spokesman Patrick Ventrell told reporters that "doesn't sound right to me."
Despite the Muslim Brotherhood's attempt to shift the blame onto Israel, leading Egyptian commentators severely criticized the army for ignoring the terrorist organizations operating in Sinai as well as warnings sent by Israeli intelligence agencies. Some commentators also fiercely condemned Morsi and accused him of encouraging radical Islam after he signed thousands of pardons for jihadists who were previously imprisoned in Egypt.
During a visit to the site of the attack in Sinai on Monday, Morsi declared that "those who committed this criminal act of terror are enemies of the Egyptian nation and they will pay dearly."
Morsi said orders had been issued to arrest the perpetrators. "There is no room for appeasing this treason, this aggression and criminality," he said. "The troops will totally control Sinai."
In a statement late Sunday, the Muslim Brotherhood urged Egyptian authorities to take all necessary measures to "confront this serious challenge to Egyptian sovereignty and to protect Sinai from all armed groups."
Egypt's military, which still holds many levers of power, called the attackers "infidels" and said it had been patient until now in the face of instability in Sinai.
"But there is a red line and crossing it is not acceptable. Egyptians will not wait for long to see a reaction to this event," it said in a statement on its Facebook page.
State news agency MENA cited a military official as saying a military funeral would be held in Cairo on Tuesday to honor the police officers who died in the attack.
Over the past year, there has been growing lawlessness in the vast desert expanse on Sinai, as Bedouin bandits, extremists and Palestinian militants from the neighboring Gaza Strip fill the vacuum, tearing at already frayed relations between Egypt and Israel.
Egyptian reports said on Monday that for the first time since the peace treaty was signed with Israel, Egyptian fighter planes circled Sinai skies. According to the report, two fighter jets were working to help find terrorists and other aircraft were expected to land at the air force base in El Arish in the coming days.
Israeli officials predicted that new Egyptian government would now change its approach to fighting terrorism in Sinai.
Officials said on Monday that for the first time since he was elected, Morsi was dealing with an internal Egyptian crisis that could undermine his whole country's security.
Egypt closed its border crossing into the Gaza Strip "indefinitely," cutting off the sole exit route for most Palestinians at the height of the Muslim fasting month of Ramadan.
Hamas, which condemned the killings of the Egyptians, also sealed smuggling tunnels after Cairo said the gunmen had used these underground links to reach Egypt. Hamas said it was working with Egypt to try to identify the culprits behind the deadly attack.
"No Palestinian could take part in such an ugly crime and in the killing of our beloved Egyptian army men in such a horrible manner," said Hamas spokesman Taher al-Nono.
Egyptian state television on Monday cited a medical source as saying six corpses that had arrived at the morgue of Arish hospital in Sinai may be the bodies of some of the assailants. It did not add further details.