Thousands of Shiites demonstrated near Manama on Saturday in a new protest against an appeals court upholding jail terms for 13 activists on charges of plotting to overthrow Bahrain's monarchy, witnesses said.

"We will not resign ourselves to it" and "we will not forget the prisoners," shouted demonstrators during the peaceful protest that was monitored by a heavy security presence. Some carried photos of those convicted.

Switzerland will on Monday file a petition signed by 52 countries calling for the International Criminal Court (ICC) to open a case on war crimes in Syria, its foreign minister said.

"Serious war crimes are being committed in Syria. We must make sure they not go unpunished," Swiss Foreign Minister Didier Burkhalter told Swiss national television TSR on Friday.

Hundreds of demonstrators rallied in central Baghdad backing Prime Minister Nouri al-Maliki on Saturday as the latest in weeks of anti-government rallies in Sunni areas of Iraq called for him to quit.

The demonstrations have worsened a political crisis, pitting Maliki against his erstwhile government partners, with the premier facing accusations of authoritarianism and sectarianism ahead of key provincial polls.

A fire in a three-storey block housing Asian workers in the Bahraini capital killed at least 13 people, the state BNA news agency reported late on Friday.

One firefighter was also injured when the building's roof collapsed during a rescue attempt, the news agency added.

More than 200 Palestinian activists were on Saturday evening refusing to leave a protest camp they set up in part of the occupied West Bank where Israel wants to build new settler homes, despite a threat to evict them.

"Members of the Israeli Civil (military) Administration told us this morning that we have one hour to evacuate the site," one of the organizers, Abir Copty, told AFP.

A man identifying himself as a senior foreign intelligence official has announced his defection from the ranks of the Syrian regime of President Bashar Assad in a video statement posted on the Internet.

"I, Jumaa Farraj Jassem, head of Section 30 of the foreign service of the General Intelligence Directorate, announce my defection from this criminal regime, as I join the ranks of this blessed revolution," said the man.

The outskirts of the Syrian capital were rocked by clashes early on Saturday a day after rebels seized a key regime airbase in the north, the Syrian Observatory for Human Rights said.

The Britain-based watchdog said two children and two men were killed when Mleha just southeast of Damascus was bombarded, and that two rebels battling forces loyal to President Bashar Assad were also killed there.

Russia called on Saturday for a political transition in Syria, as Switzerland prepared to petition the International Criminal Court to open a case on war crimes in the country.

Violence raged unabated with regime warplanes carrying air strike near the capital, a car bomb explosion in Damascus province and the murder of an athletics champion shot dead by gunmen, said the Syrian Observatory for Human Rights.

An Egyptian police officer and six recruits were wounded on Friday when gunmen attacked their patrol in the Sinai Peninsula, security officials said.

The patrol had been tasked with protecting the cross-Sinai pipeline that supplies Egyptian gas to Israel and Jordan and which has been the target of 15 separate attacks since 2011.

Rached Ghannouchi, who heads Tunisia's ruling Islamist party, warned on Friday, three days ahead of the revolution's second anniversary, against the country sliding into chaos amid social unrest.

"Several countries have succeeded in ousting regimes but not then installing a democratic state because liberties become corrupted, as in Somalia," the Ennahda chief told a gathering of supporters in the capital's Raoued suburb.