Syrian opposition head Burhan Ghalioun called on Sunday for a "battle of liberation" against the regime until the United Nations takes action under Chapter Seven which allows military intervention.

"I call on the Syrian people to lead a battle of liberation and dignity, relying on its own forces, on the rebels deployed across the country and the Free Syrian Army brigades and friends," he told a news conference in Istanbul.

A Bahraini court on Sunday jailed six Shiites for 15 years for plotting attacks in the Gulf kingdom, including an to attempt to blow up the causeway with Saudi Arabia, lawyers said.

The six men arrested in November chanted in defiance: "victory is close," after the verdict was announced, according to one of the lawyers attending the hearing in Manama.

More than 13,000 people have been killed in Syria since an anti-regime revolt broke out in March 2011, Rami Abdel Rahman of the Syrian Observatory for Human Rights told Agence France Presse on Sunday.

"In total, 13,004 people were killed," Abdel Rahman said, adding that 9,183 of them were civilians.

Tens of thousands of Moroccans took to the streets of Casablanca on Sunday in the largest opposition protest since an Islamist-led government took office, reflecting mounting tensions over unemployment and other social woes.

The protest was organized by trade unions which accuse Prime Minister Abdelilah Benkirane of failing to deliver on the pledges of social justice that brought his party to power in the wake of the Arab Spring.

The Syrian government is "not at all" responsible for the massacre of at least 92 people in the central town of Houla which has sparked an international outcry, foreign ministry spokesman Jihad al-Makdissi said on Sunday.

"We completely deny responsibility for this terrorist massacre against our people," Makdissi told a news conference.

A criminal court has convicted one of former Egyptian president Hosni Mubarak's closest aides of corruption and jailed him for seven years, Egypt's official news agency said Sunday.

Sunday's ruling also fined Zakaria Azmi 36.3 million pounds ($6 million).

Britain is to haul in Syria's top diplomat in London following the killing of 92 people -- a third of them children -- in the shelling of the town of Houla, the Foreign Office said Sunday.

Syria's charge d'affaires -- their ambassador has been withdrawn -- will meet with one of the top civil servants in the Foreign Office on Monday so Britain can stress its "condemnation" over the incident.

The Syrian army kept up its bombardment of rebel strongholds on Sunday despite an international outcry over the killing of 92 people, a third of them children, in the shelling of a central town.

Arab and Western governments expressed outrage at the "massacre" in the town of Houla on Friday and Saturday.

Arab League foreign ministers are to hold an emergency meeting on a massacre in Syria in which U.N. observers say government forces killed 92 people, the bloc's current president Kuwait said on Sunday.

"Kuwait will contact members of the Arab League to hold an emergency ministerial meeting to study the situation and take measures to put an end to the oppressive practices against the Syrian people," said a foreign ministry statement cited by the official KUNA news agency.

The administration of President Barack Obama is considering working with Russia on a plan calling for the departure of Syrian President Bashar Assad under a proposal modeled on the transition in Yemen, The New York Times reported Sunday.

The newspaper said the plan calls for a negotiated political settlement that would satisfy Syrian opposition groups but that could leave remnants of Assad's government in place.