Egypt's state prosecutor said Sunday that Muslim Brotherhood supreme guide Mohammed Badie would stand trial in a second case over clashes in which several demonstrators were killed, judicial sources said.

Fourteen people, including several top figures in the Brotherhood, the group from which ousted president Mohammed Morsi hails, will stand trial along with Badie at a date that has yet to be decided, the sources added.

Former presidential candidate and opposition leader Amr Moussa was on Sunday elected head of Egypt's 50-member panel that has been tasked with drawing up a new constitution.

The panel was named a week ago by interim president Adly Mansour to draw up a revised constitution in the wake of the ouster by the army of former president Mohammed Morsi on July 3.

U.S. Secretary of State John Kerry said Sunday that Israel and the Palestinians are determined to push forward with peace talks.

"Despite tough decisions that have to be made and despite pressure that exists on both sides... both the Palestinians and Israelis have remained steadfast in their commitment to continuing the talks," Kerry said in Paris after a meeting with Arab League officials.

Iran's foreign minister slammed potential U.S.-led airstrikes against Syria as "illegal" on a visit to Baghdad Sunday, while his Iraqi counterpart warned they would hinder efforts towards a political solution.

Mohammad Javed Zarif said military action was barred under the United Nations charter, but Washington is pressing for the strikes in response to an alleged chemical weapons attack the White House says was carried out by the regime of Syrian President Bashar Assad.

Iraq's most senior Sunni politician cautioned against possible U.S.-led strikes against Syria on Sunday, warning they would "ignite a fire" in the Middle East that could spread across the region.

The remarks were a rare criticism by a Sunni Arab leader of the potential strikes, currently being pushed by the White House against Damascus over an alleged chemical weapons attack last month.

Pope Francis on Sunday lashed out at what he termed "commercial war to sell arms" as he led mass prayers in Saint Peter's Square for Syria.

In his traditional weekly prayers in front of an unusually large crowd of faithful in the Vatican, the leader of the world's 1.2 billion Catholics called for his followers to "say no to violence in all its forms, to the proliferation of weapons and their illegal trade."

British Foreign Secretary William Hague called Sunday for a strong response to the use of chemical weapons in Syria, saying the issue went wider than the conflict in the Middle Eastern country.

Hague said that although the British parliament had rejected joining military action against Syria, he backed anticipated U.S.-led air strikes to stop President Bashar Assad's regime using poison gas again.

U.S.-led military strikes on Syria would boost all of the country's opposition forces, including jihadists, but would not be enough to precipitate the fall of Bashar Assad's regime, analysts say.

U.S. President Barack Obama is seeking congressional authorization for limited military strikes on Syria in response to an alleged chemical weapons attack in the suburbs of Damascus on August 21.

The Pentagon is readying more intense and longer attacks on Syria than originally planned, set to last three days, the Los Angeles Times reported Sunday.

War planners now aim to unleash a heavy barrage of missile strikes to be followed swiftly by additional attacks on targets that may have been missed or remain standing after the initial launch, the Times cited officials as saying.

Syrian rebels, including jihadists linked to Al-Qaida, have taken control of the historic Christian town of Maalula, north of Damascus, a watchdog and a resident said on Sunday.

Maalula is home to around 5,000 residents and is of strategic importance for the rebels, who are trying to tighten their grip around the capital Damascus, adding a northern post to existing bases in the south and west of the city.