African leaders agreed Friday on a peace plan that rules Libyan leader Moammar Gadhafi out of talks with rebels to end the four-month conflict in his country, a top official said.

The plan, which has to be presented to the Libyan regime and rebels, says "Gadhafi must not participate in negotiations", the head of the African Union peace council, Ramtane Lamamra, told Agence France Presse.

A U.S. vessel aiming to break Israel's naval blockade on Gaza sailed from Greece Friday but was promptly stopped by coastguards for defying a ban, an activist on board said.

The Audacity of Hope set sail for Gaza without warning, leaving behind nine other ships in a pro-Palestinian international flotilla.

Hundreds of thousands of protesters staged huge rallies across Yemen on Friday calling for the departure of all figures in the regime of President Ali Abdullah Saleh, who has been hospitalized in Riyadh for nearly a month.

Saleh supporters also massed in Sanaa to express what they described as their "loyalty" to the veteran leader, who is receiving treatment from wounds sustained in an explosion at his presidential compound on June 3.

Syrian security forces on Friday killed 11 civilians as more than half a million people took to the streets across the country to demand the departure of President Bashar al-Assad, activists said.

Six people died in the central city of Homs when security forces opened fire to quash protests, two were killed in Damascus and one in Daraya, near the capital, activists told Agence France Presse.

France insisted Friday that weapons it supplied to rebels fighting Libyan leader Moammar Gadhafi were for "self-defense" in line with a U.N. resolution, after Russia and others voiced concern.

"Civilians had been attacked by Gadhafi's forces and were in an extremely vulnerable situation and that is why medicine, food and also weapons of self-defense were parachuted," Foreign Minister Alain Juppe said.

Israeli police on Friday limited access to the al-Aqsa and Dome of the Rock mosques in Jerusalem as a precautionary measure a day after clashes in east Jerusalem, a spokeswoman said.

"This Friday we are preventing access to the plaza for Muslim men less than 45 years old," police spokeswoman Luba Samri said, although she denied the restriction was linked to Thursday night's violence.

Time is running out for Syrian President Bashar Assad, U.S. Secretary of State Hillary Clinton said Friday amid reports of anti-regime protests in the country's second city Aleppo.

Clinton, who spoke on a visit to Lithuania, criticized the regime's incoherence in authorizing an opposition meeting and cracking down on political dissent.

U.N. chief Ban Ki-moon welcomed Thursday a move by Bahrain to launch a probe to investigate the violent repression of pro-democracy protests, but stressed its independence was key.

The secretary-general "welcomes this development and underscores that the commission should be granted full access to all individuals, organizations and information relevant to the investigation," his spokesperson said.

Moroccans voted Friday in a referendum on curbing the near absolute powers of King Mohammed VI, who has offered reforms in the wake of protests inspired by pro-democracy uprisings around the Arab world.

Faced with demonstrations modeled on the Arab Spring protests that ousted long-serving leaders in Tunisia and Egypt, Mohammed VI announced the referendum last month to devolve some of his powers to the prime minister and parliament of the north African country.

The U.N. Security Council on Thursday extended the mandate of the U.N. force monitoring the ceasefire in the Golan Heights between Syria and Israel by another six months.

The unanimous decision extends the mandate of the U.N. Disengagement Observer Force (UNDOF) to December 31, 2011.