Egypt's defense minister warned on Sunday that the army will intervene if violence breaks out in the country where opponents of President Mohammed Morsi are planning rallies against him this month.

"The armed forces have the obligation to intervene to stop Egypt from plunging into a dark tunnel of conflict and infighting," Abdel Fattah al-Sisi warned ahead of the first anniversary of Morsi's election, as opposition leaders clamoured for his resignation.

An Egyptian court said on Sunday that Hizbullah and Hamas helped prisoners, including current President Mohammed Morsi, escape during the 2011 uprising.

The head of the court in the Suez Canal city of Ismailiya asked the state prosecutor to investigate the circumstances of the January 2011 breakout from the Wadi Natrun prison, northwest of the capital.

Leading Egyptian dissident Mohammed ElBaradei urged President Mohammed Morsi on Saturday to resign for the sake of national unity, ahead of planned opposition-backed rallies calling on the Islamist leader to step down.

"For Egypt's sake, I call on President Mohammed Morsi to resign and give us the opportunity to begin a new phase based on the principles of the revolution, which are freedom and social justice," ElBaradei said.

Egypt's airports will raise their alert level to "high" ahead of June 30 when opposition-backed protesters plan to demonstrate against President Mohammed Morsi, security officials said on Saturday.

"An emergency plan will be put in place from June 28 until July 1," the head of Cairo airport security, General Magdy al-Yussri, told reporters.

Egyptian President Mohammed Morsi has repeated a call for dialogue with the opposition in an attempt to mitigate deep political divisions ahead of planned rallies later this month calling for his resignation.

"I have said it before. I urge everyone to sit together to discuss what would achieve the interests of our nation," Morsi said in an interview published in the state-owned Akhbar al-Youm newspaper.

Islamist parties have called a mass rally Friday as a show of force ahead of planned opposition protests calling for Islamist President Mohamed Morsi to go, highlighting Egypt's highly charged political divide.

The Freedom and Justice Party (FJP), the political arm of the powerful Muslim Brotherhood from which Morsi hails, and several other groups, have called for a "million-man march to protect the revolution" in Cairo's Nasr City neighborhood.

Ethiopia used a regional meeting Thursday aimed to promote cooperation over the Nile river to urge other nations to ratify a controversial water deal fiercely opposed by Egypt.

Addressing water ministers and officials from the 10-nation Nile Basin Initiative (NBI), Ethiopia's Minister for Water and Energy Alemayehu Tegenu challenged Egypt's historical majority control usage of the river water.

Authorities in Egypt have valued the wealth of former dictator Hosni Mubarak, his wife and their two sons at nine billion Egyptian pounds ($1.2 billion, 900 million euros), the state prosecutor said Thursday.

It is the first time that an official source has given a figure for the Mubaraks' wealth, the subject of speculation since a popular uprising in February 2011 toppled the regime.

An Egyptian court on Thursday ordered the release of former prime minister Ahmed Nazif who has been detained for more than two years on fraud charges, media reported.

The Giza Criminal Court ordered Nazif's release "so long as he is not being detained on other charges," it said in a statement quoted by the official MENA news agency.

A group of 30 Egyptians and Emiratis have been charged by the UAE authorities for allegedly setting up an illegal branch of Egypt's Islamist Muslim Brotherhood, a prosecutor said on Wednesday.

The suspects have been referred to the Gulf nation's State Security Court, prosecutor Ahmed al-Dhanhani said.