Egypt's ousted strongman Hosni Mubarak suffered a stroke in prison on Tuesday as authorities mulled transferring him to hospital, state media reported.

Mubarak did not lose consciousness during the stroke, the official MENA news agency reported. It had previously that doctors treated the former president with a defibrillator earlier because his "heart stopped."

A previously unknown Islamist group has claimed responsibility for an attack on Israel by militants who crossed from Egypt, according to a video message reported by SITE Intelligence on Tuesday.

The video featured a militant announcing the setting up of a group named the "Mujahideen Shura Council in the Environs of Jerusalem," while other footage showed two gunmen saying they were about to launch the attack, according to the video posted by the US-based monitoring service.

Ousted Egyptian strongman Hosni Mubarak's last prime minister, Ahmed Shafiq, won a presidential election runoff, his campaign team insisted on Tuesday, disputing his Islamist rival's claim of victory.

"We are certain that the next president of Egypt is General Shafiq," his campaign spokesman Ahmed Sarhan told a news conference.

France on Tuesday voiced concern that Egypt's military appeared to be clinging to power after a pivotal presidential vote and called for a speedy return to democracy.

Egypt's ruling military council announced de facto martial law just after the election, giving the armed forces control over the legislature and state budget.

Egypt's parliament still has the power to legislate, the Muslim Brotherhood's political arm said on Monday, despite the ruling military's decision to take back power after a court annulled the body.

"The parliament remains valid and holds legislative power and control," the Freedom and Justice Party (FJP) said hours after the Brotherhood declared its candidate, Mohammed Mursi, had won presidential elections.

The Pentagon expressed serious concern Monday after the Egyptian military declared sweeping new powers just as ballots were being counted in a pivotal presidential vote.

"We're deeply concerned about new amendments to the constitution declaration, including the timing of their announcements as polls were closing for the presidential election," spokesman George Little told reporters.

France denounced a deadly strike on Israel Monday by militants who had sneaked across the Egyptian border and urged restraint by all parties to prevent a spike in tensions.

An Israeli civilian was killed in the ambush, which sparked a firefight that left at least two gunmen dead. It mirrored a strike in August 2011 in which gunmen from Sinai staged ambushes in southern Israel, killing eight.

Egypt's ruling military pledged again on Monday to hand power to the winner of this weekend's election by June 30 and said he would enjoy full presidential powers.

The military council will transfer power to the new president, who will swear his oath before the constitutional court by "June 30, this month," Mahmduh Shahin, one of the ruling generals, said at a news conference.

Israeli Defense Minister Ehud Barak on Monday blasted Egypt over a "disturbing deterioration" in its security control over the lawless Sinai peninsula after a deadly border attack killed an Israeli civilian.

And he urged Egypt's incoming leadership to "take responsibility" for security in the strife-torn peninsula which shares a 240-kilometer (150-mile) border with Israel.

Israel was still hunting for up to four gunmen who on Monday infiltrated the Egyptian border and staged a deadly ambush, killing one Israeli and sparking a firefight which left two militants dead.

The incident began around 6:00 am (0300 GMT) when a group of up to six gunmen opened fire towards a convoy of vehicles carrying Israeli construction workers to a site where they are building part of the vast border fence, the army said.