Militants wounded three Egyptian policemen in the Sinai Peninsula on Saturday in an ambush of their vehicle with a rocket propelled grenade, a security official said.

The militants attacked the policemen near the north Sinai town of Sheikh Zuwayid, roughly 15 kilometers (9 miles) west of the Gaza border, as the policemen were returning from an operation, the official said.

The new defense minister appointed by Egypt's Islamist president has pledged to uphold the strong military ties between Cairo and Washington, Pentagon chief Leon Panetta said Tuesday.

In a surprise move Sunday, President Mohamed Morsi retired Field Marshal Hussein Tantawi -- head of the military council that assumed power after the ouster of Hosni Mubarak -- and replaced him with Abdel Fattah al-Sissi.

An Egyptian court sentenced 14 Islamists to death on Tuesday for the 2011 murder of seven people at a bank and a police post in the Sinai Peninsula, scene of mounting violence near the border with Israel.

The court in the Suez Canal city of Ismailiya convicted the 14 of carrying out the attacks in June and July last year on behalf of the hardline group Tawhid wal Jihad (Monotheism and Holy War).

Egypt's security forces exchanged fire on Tuesday with militants in the Sinai peninsula, sources said, as the military continued its campaign against Islamists in the lawless region.

A patrol comprising army soldiers and police came under attack from unidentified gunmen and fired back, the security sources said, adding that there were no casualties or arrests reported.

A Gaza official says Egypt is opening its border crossing with the Hamas-ruled coastal territory for three days ahead of a major Muslim holiday this weekend.

Maher Abu Sabha of the Gaza border authority says the crossing will open to traffic in both directions later on Tuesday.

Television boss Tawfiq Okasha and newspaper journalist Islam Afifi will be tried for "incitement" and insulting Egyptian President Mohammed Morsi, the prosecutor's office said on Monday.

Okasha, owner of the private channel Al-Faraeen, is accused of "incitement to murder" of the Islamist president, said Adel Saeed, a spokesman for the prosecutor general.

Israel is watching "with great concern" the developments in Egypt where Islamist President Mohammed Morsi ousted his powerful defence minister and army chief following a deadly attack in Sinai.

In a surprise move aimed at curbing the Egyptian army's sweeping powers, Morsi on Sunday forced retirement upon both Field Marshal Hussein Tantawi and the army's Chief of Staff Sami Anan.

Egypt's Islamist President Mohammed Morsi has denied trying to marginalize the army after he ordered the retirement of his powerful defense minister, saying he was acting in the interests of the country.

However, the Egyptian press on Monday described Morsi's move as "revolutionary", with some saying it was aimed at ending the power of the Supreme Council of the Armed Forces (SCAF).

Egypt's Islamist President Mohammed Morsi on Sunday ordered the surprise retirement of his powerful defense minister and scrapped a constitutional document which handed sweeping powers to the military.

Field Marshal Hussein Tantawi, who ruled Egypt for more than a year after the revolution that toppled former president Hosni Mubarak, was replaced by Abdel Fattah al-Sissi.

Gaza's Hamas rulers on Sunday insisted that so far, there was no proof that any Palestinian was involved in a deadly attack on Egyptian troops in northern Sinai which left 16 dead.

"Until now, neither the Palestinian nor the Egyptian security services have proof that any party in Gaza supported or executed the attack," said senior Hamas official Salah al-Bardawil.