Israel's President Shimon Peres accused Iran Monday of encouraging the Palestinians to continue rocket attacks on Israel rather than negotiating a ceasefire, saying "they are out of their mind."

At the same time, Peres praised Egypt's President Mohammed Morsi for the constructive role he has played in the intensifying crisis.

The U.N. Security Council hit deadlock Monday on a statement on the Gaza conflict with the United States saying it opposes any action that undermines efforts to reach a ceasefire.

But Russia warned that unless an Arab-proposed statement calling for Israel-Hamas hostilities to end was agreed by Tuesday morning it would press for a vote on the full council resolution -- setting up a potential veto clash with the United States.

Protesters in Egypt's capital clashed with police on Monday during a protest to mark a year since a five-day long street battle with security forces in which dozens of protesters were killed, witnesses said.

The clashes erupted when demonstrators tried to destroy a concrete barrier security forces had put up to end last year's fighting with activists who wanted the military rulers at the time to transfer power to a civilian government.

European Union foreign ministers, in a new blow to President Bashar Assad's regime, on Monday said they viewed Syria's just-formed National Coalition to be the "legitimate representatives" of the Syrian people.

A statement from the bloc's 27 ministers welcomed the November 11 formation of the National Coalition for Syrian Revolutionary and Opposition Forces and said: "The EU considers them legitimate representatives of the aspirations of the Syrian people."

U.N. leader Ban Ki-moon arrived in Cairo on Monday to bolster Egypt-mediated efforts for a ceasefire in Gaza which officials said could end the conflict before it worsens with a possible Israeli ground invasion.

Ban will inject heavyweight impetus into the peace effort, meeting Foreign Minister Mohammed Kamel Amr and Arab League chief Nabil al-Arabi before flying to see Israeli Prime Minister Benjamin Netanyahu and Palestinian chief Mahmoud Abbas.

A newly formed Syrian opposition bloc that has received Arab and international backing is to be based in Egypt, its head Ahmed Moaz al-Khatib told the official MENA news agency on Monday.

"It has been decided that the Syrian National Coalition will have its headquarters in Egypt," Khatib was quoted as saying after talks with Egyptian Foreign Minister Mohammed Kamel Amr.

The newly formed Syrian opposition coalition is likely to get an offering of support from the European Union on Monday, an EU official said, in what would be a significant vote of confidence for a movement struggling to prove its credibility and gain the trust of the country's factions.

Such a move would not amount to official diplomatic recognition because that can only be decided by each EU country individually. But if the bloc's 27 foreign ministers meeting in Brussels decide that the coalition is a legitimate voice for Syria's people it would be a major step forward in the West's acceptance of the group.

Hundreds marched on Cairo's Tahrir Square on Monday to mark one year since deadly clashes that left 45 people dead, piling pressure on President Mohamed Morsi to bring his predecessor's police to account.

Around 50 political parties and movements took part in the commemoration, furious that a year after the clashes on Mohammed Mahmoud street, no police officers have been held accountable for the deaths.

An Iranian semi-official news agency says the country has started building a $10 billion natural gas pipeline to Syria as part of efforts to boost its energy sector that has been battered by international sanctions.

Monday's report by the Fars news agency says the 1,500 kilometer (750 mile) pipeline will pass through Iraq before reaching Syria. It says Iran begun construction of the first phase of the project involving a 225 kilometer (140 mile) stretch at an estimated cost of $3 billion.

Hamas chief Khaled Meshaal said Monday his movement is committed to efforts to secure a truce with Israel, but insisted the Jewish state must lift its six-year blockade of the Gaza Strip.

"We are committed to a ceasefire, but Israel must stop its aggression," Meshaal said. “We don't want an escalation, because Hamas and all resistance factions are courageous but they are also rational," he added.