JEDDAH/AMMAN (Reuters) - Bombs exploded in three districts of the Syrian capital Damascus on Tuesday, killing and wounding dozens, and gunmen shot dead the brother of the parliament speaker in the latest rebel attack on a figure associated with the ruling elite.
The opposition said at least 100 more people were killed elsewhere in the civil war, and Britain suggested offering President Bashar al-Assad immunity from prosecution as a way of persuading him to leave power.
"Anything, anything, to get that man out of the country and to have a safe transition in Syria," British Prime Minister David Cameron told Al Arabiya news network in Abu Dhabi before flying on to Saudi Arabia.
Syrian state media said at least 10 people were killed and 30 wounded by an explosion in the Hai al-Wuroud district in the northwest of the capital.
The hilltop neighbourhood is situated near a barracks and housing for elite army units, and is home to members of Assad's Alawite sect, an offshoot of Shi'ite Islam. Syria's rebellion in is drawn mainly from the Sunni Muslim majority.
Opposition activists said three explosions were heard in Hai al-Wuroud and at least 15 people killed. A car bomb also detonated near a shopping mall in the mixed neighbourhood of Ibn al-Nafis, killing and injuring several people, they said.
On Tuesday evening, activists reported another car bombing, this time near a mosque in the Sunni working-class district of al-Qadam in south Damascus, causing dozens more casualties. Buildings were damaged and bodies buried under debris that clogged the streets, the activists told Reuters.
"Lots of people were hit inside their apartments. Rescue efforts are hampered because electricity was cut off right after the explosion," said Abu Hamza al-Shami.
"There is a state hospital nearby but we are afraid to take the wounded there because they could be liquidated."
Bomb attacks along sectarian lines have escalated in the 19-month-old anti-Assad uprising. Last month several bombs went off during the Muslim Eid holiday near mosques in Sunni districts and the Damascus suburbs, killing and injuring dozens.
Officials and their families are increasingly being targeted by assassins as violence spreads in the capital. Victims have included parliamentarians, ruling Baath party officials, and even actors and doctors seen as Assad supporters.
State television said gunmen had assassinated Mohammed Osama al-Laham, brother of the speaker of parliament, in Damascus's Midan district. No group claimed immediate responsibility.
Peace envoy Lakhdar Brahimi warned that Syria, where some 32,000 people have died in the upheaval, could end up a collapsed state like Somalia, prey to warlords and militias.
Opposition factions were meeting in Qatar in an effort to forge a common front. The opposition has remained divided between Islamists and secularists, civilians and armed fighters, and between exiles and those working inside the country.
More than 100 people were killed across the country on Tuesday, said the Syrian Observatory for Human Rights, a pro-opposition body based in Britain that compiles activist reports.
Air strikes killed 17 people, including women and children, in the Damascus suburb of Kfar Batna, it said. Video footage of the raid's aftermath posted on the Internet, which could not be verified, showed a toddler with a severed head and the torso of a young man, his head and limbs gathered near him by rescuers.
Insurgents killed 12 soldiers and wounded 20 in an attack on a convoy of off-road vehicles in the northern province of Idlib.
Air strikes and artillery barrages unleashed by the Syrian military in the last few weeks have wrecked whole districts of the capital, as well as parts of towns and cities elsewhere.
Yet, for all their firepower, Assad's forces seem no closer to crushing their lightly armed opponents, who in turn have so far proved unable to topple the Syrian leader.
"Of course I would favour him facing the full force of international law and justice for what he's done," Cameron said of Assad. "I am certainly not offering him an exit plan to Britain. But if he wants to leave he could leave; that could be arranged."
It was unclear if Cameron had spoken to other U.N. Security Council members about the idea - which could involve offering Assad immunity from prosecution if he accepted asylum in a third country. Nor was it clear what country would take him.
The U.N. human rights office has said Syrian officials suspected of committing or ordering crimes against humanity should face prosecution at the International Criminal Court. U.N. investigators have been gathering evidence of atrocities committed by rebels as well as by Assad loyalists.
The United Nations has put Syria's government on a "list of shame" of countries that abuse children, saying Assad loyalists have killed, maimed, tortured and detained children as young as nine. Leila Zerrougui, Special Representative of the Secretary-General for Children and Armed Conflict, told Reuters on Tuesday the body was also investigating the opposition.
"We have received information that the opposition also violates children by using them in bombings, and by bombing areas where there are children," she said.
Brahimi, the U.N.-Arab League envoy to Syria, told the London-based al-Hayat newspaper he did not expect ethnic or sectarian partition there. "What I am afraid of is worse ... the collapse of the state and that Syria turns into a new Somalia."
Russia and China have blocked three Western-backed U.N. Security Council draft resolutions against Assad. At the United Nations, diplomats quoted a senior U.N. official as telling the Security Council that Brahimi had urged Russia to be "more pro-active" in resolving the Syrian crisis.
U.N. political affairs chief Jeffrey Feltman also told the closed-door meeting of the council that he had credible reports of government forces using cluster bombs, the envoys said.
Human rights groups have reported in the past that Syria used cluster munitions. Such weapons, which spread bomblets that explode over an area, are banned by most countries. But Syria - like the United States, Russia and China - has not signed up to the treaty outlawing them. Human rights groups view their use in areas populated by civilians to be a war crime.
Russian Foreign Minister Sergei Lavrov urged the Syrian opposition to enter talks with the authorities to end the crisis and abandon a precondition that Assad step down.
"The most important thing is stopping the violence immediately. If it is more important to the other side to change the Assad regime, then they want to continue the bloodbath in Syria," Lavrov said in Amman after meeting former Syrian Prime Minister Riad Hijab, who defected to Jordan in August.
Hijab said Assad's removal was "the only way out".
Assad's foes have failed to unite, making it harder for the outside world to support or arm them.
Prominent dissident Riad Seif has proposed a new 50-member unity council. But the head of the widely criticised Syrian National Council (SNC), which is based abroad, said it should retain a "central role" in any opposition configuration.
A Doha-based diplomat said SNC members feared their group risked losing influence in the new civilian body, which would later choose an interim government and coordinate with armed rebel groups. Seif's initiative is to be debated on Thursday at the opposition meeting in Qatar.
Additional reporting by Suleiman al-Khalidi in Amman, Oliver Holmes in Beirut, Rania el-Gamal and Regan Doherty in Qatar, Emad Omar in Cairo and Louis Charbonneau in New York; Writing by Peter Graff and Alistair Lyon; Editing by Mark Heinrich