By Oliver Holmes
BEIRUT, Sept 8 (Reuters) - Syrian troops stormed into a Palestinian refugee district in Damascus, opposition activists said, after a four-day artillery assault on the southern suburb where rebels fighting to oust President Bashar al-Assad have dug in.
Assad's forces have preferred to use air power and artillery to hit areas where rebels are positioned and infantry raids normally occur only once many have fled. Activists said they feared for civilian inhabitants in the latest offensive.
Assad's use of military force to quell an uprising that began almost 18 months ago as a peaceful pro-democracy movement has cost him many allies in the Arab and Muslim world and caused a trickle of defections from Syrian government and army ranks.
Two Syrian diplomats in Malaysia announced late on Friday that they had joined the opposition, according to a report by pan-Arab television channel Al Arabiya.
Two men identifying themselves as First Secretary Imad Ahmar and Attaché Mahmoud Obedi from Syria's Kuala Lumpur embassy read out a statement on the channel declaring their "support for the Syrian people's revolution against the tyrannical regime".
But the defections so far are seen largely as symbolic and Assad has increasingly relied on a close circle of relatives and senior members of his minority Alawite sect dominating the ruling elite to maintain his grip on power.
CAMP HOSPITAL STORMED
Syrian activist Abu Yasser al-Shami said that his friends living in Yarmouk, a densely populated Palestinian refugee camp where 10 people were killed on Friday in shelling, had fled the area on Saturday morning after government troops swept in.
"Assad's forces stormed al-Basel hospital in Yarmouk Camp and arrested many of the injured civilians," he said over Skype.
When insurgents thrust into central parts of the capital in July, they were swiftly pushed back to southern districts, like Yarmouk, where there is a thinner state security presence.
But residents complain that the army uses indiscriminate artillery and air strikes. Palestinians have been divided over whether or not to support Assad, but there are signs that more and more are now starting to back the uprising.
The Syrian Observatory for Human Rights, an opposition watchdog based in London, said shells rained down on Hajar al-Aswad district, which neighbours Yarmouk, on Saturday.
It said 170 people were killed in bloodshed on Friday across the country, many of them in Damascus and northern Aleppo, where rebels say they control more than half of what is Syria's most populous city and commercial centre.
The Observatory says more than 23,000 people have died in an uprising that has lasted more than 17 months. Around 200,000 Syrians have fled to neighbouring Turkey, Jordan and Iraq.
The conflict is spilling over Syrian borders and has raised sectarian tension in the region given that the revolt has been led by majority Sunni Muslims against a president who is Alawite, an offshoot of Shi'ite Islam.
ARREST IN SYRIA-RELATED KIDNAPPING
Lebanon's army forces raided a southern district of Beirut late on Friday and arrested a member of a powerful Shi'ite clan which has claimed responsibility for the kidnapping of 20 Syrians and a Turkish businessman.
The army arrested Hassan Meqdad, from the Meqdad clan, which abducted the men on Aug. 15 in what they said was a response to the capture of one of their kinsmen in Damascus by the rebel Free Syrian Army.
Damascus continues to exert influence over is smaller neighbour and even had troops garrisoned in Lebanon until 2005.
The Meqdads are one of many armed groups in Lebanon which continue to exert power. The northern port city of Tripoli has seen sporadic clashes between Assad's supporters and his foes.
"The (army) continues its search for a number of culprits who fled to various Lebanese regions and plans to maintain its work for the release of all hostages," an army statement said. It added that large quantities of weapons and ammunition were seized during the raid on the Rweiss district of Beirut.
The United States has accused Russia and China of effectively prolonging Syria's bloodletting by blocking efforts at the U.N. Security Council to approve tough sanctions aimed at reining in the Assad government.
Russian Foreign Minister Sergei Lavrov said at a summit of Pacific rim states that Moscow and Western powers remained at loggerheads over how to defuse the conflict - a diplomatic impasse in which Western officials say violence has flourished.
"Our U.S. partners prefer measures like threats, increased pressure and new sanctions against both Syria and Iran. We do not agree with this in principle," Lavrov told reporters. Russia and Iran are Assad's closest allies.
Lavrov said Russia expected the Security Council later this month to formally endorse an agreement brokered by former U.N. Syria envoy Kofi Annan which envisages a transitional governing authority for Syria.
Washington has angered Russia by going outside the United Nations to work with allies on the Syrian opposition's behalf. But U.S. Secretary of State Hillary Clinton told Lavrov it was possible to return to the United Nations if Moscow and Beijing were ready to forego their vetoes and back stronger measures.
Despite major defections and a July 18. explosion in Damascus that killed four top generals, including President Bashar Assad's brother-in-law, the regime's inner circle is still powerful and united against the opposition. Assad's inner circle includes his younger brother, Maher, who commands the forces in charge of protecting the capital. It also includes the heads of the four intelligence agencies playing a major role in the crackdown. Although regime forces lost parts of the northern city of Aleppo, Syria's largest, government troops still control most cities, while the opposition dominates large parts of the countryside. <em>Caption: This June 13, 2000, file photo shows Syrian President Bashar Assad, right, his brother Maher, center, and brother-in-law Major General Assef Shawkat, left. (AP Photo, File)</em>
Free Syrian Army
The main rebel fighting force for more than a year, the Free Syrian Army includes lightly-armed volunteer militiamen and defectors from Assad's military. Its overall strength and structure is unclear, but tens of thousands are believed be loyal to the group. The rebels have control over some northern areas, allowing movement of fighters and supplies from Turkey and Lebanon. Anti-Assad forces have failed to maintain any strategic footholds in big cities, being driven back from key neighborhoods in Homs earlier this year and now apparently losing ground in the largest urban center, Aleppo. The battles also suggest only weak direction from central commanders - including Turkey-based Free Syrian Army leader Riad al-Asaad. <em>Caption: In this citizen journalism image provided by Shaam News Network SNN, taken on Sunday, Aug. 12, 2012, Free Syrian Army soldiers pose for a photograph, in Sarmada, Idlib province, northern Syria. (AP Photo/Shaam News Network, SNN)</em>
Syrian National Council
Based in Istanbul, the SNC has emerged as the main political opposition to Assad and has pushed for international recognition as the legitimate representative of the uprising, despite rifts with other Syrian factions. The group also has been hit by internal feuds that have led some senior members to quit. The current leader, Abdelbaset Sieda, is a Swedish-based activist for Syria's minority Kurdish community. The SNC has gained support from many countries in the West and Arab world, but it has not galvanized international backing, and critics complain its senior leadership is made up mostly of exiles out of touch with their homeland. <em>Caption: The members of the Syrian National Council and its head Abdulbaset Sieda, center, arrive for a meeting with Turkey's Foreign Minister Ahmet Davutoglu in Ankara, Turkey, Monday, July 23, 2012.(AP Photo/Burhan Ozbilici)</em>
The National Coordination Committee for Democratic Change
A rival to the SNC, the National Coordination Committee is led by opposition figures inside Syria, many of them former political prisoners. SNC members accuse the group of being far too lenient and willing to engage in dialogue with the regime. In turn, the National Coordination Committee accuses the SNC of being a front for Western powers and willing to open the door to the Muslim Brotherhood and other conservative Islamist factions. <em>Caption: Member of the National Coordination Committee for Democratic Change, Morhaf Mickael speaks during a meeting of Syrian opposition parties in Brussels on Sunday, June 24, 2012. (AP Photo/Virginia Mayo)</em>
On Assad's side are traditional Shiite allies Iran and Lebanon's Hezbollah. <em>Caption: In this photo released by the Syrian official news agency SANA, Iran's Supreme National Security Council, Saeed Jalili, meets with Syrian President Bashar Assad in Damascus, Syria, Tuesday, Aug. 7, 2012. (AP Photo/SANA)</em>
The regime also has important political cover from Russia and China, which have used their Security Council vetoes to prevent U.N. sanctions on Syria. <em>Caption: In this Jan. 25, 2005 file photo, Syrian President Bashar Assad, left, and Russian President Vladimir Putin shake hands during a signing ceremony in the Kremlin, Moscow. (AP Photo/Sergei Chirikov)</em>
The rebels have built an array of regional support that includes the wealthy Gulf states - led by Iran rival Saudi Arabia - and neighboring Turkey, which offers key supply routes. The West also backs the rebel forces, but has so far opposed mobilizing international military support similar to the NATO-led airstrikes that helped topple Moammar Gadhafi's regime in Libya. <em>Caption: From left, Bahrain's Foreign Minister, Sheik Khalid bin AhmedI bin Mohammed al-Khalifa, Saudi Arabia's Foreign Minister Prince Saud al-Faisal, his Turkish counterpart Ahmet Davutoglu and United Arab Emirates' Sheikh Abdullah bin Zayed al-Nahayan seenduring a group photo during the Gulf Cooperation Council (GCC) Foreign ministers meeting in Istanbul, Turkey, Saturday, Jan. 28, 2012 (AP Photo)</em>
Syria has drawn foreign fighters just as other recent conflicts such as Iraq and Afghanistan. No credible count on them exists, but anecdotal evidence suggests foreigners are coming to fight Assad. Rebel commanders downplay the presence of foreign fighters, saying their cause is a purely Syrian uprising. Mohammed Idilbi, a Syrian activist based in Turkey, says foreign ranks include Libyans, Yemenis, Tunisians and Lebanese. On Saturday, Syria's official SANA news agency claimed four Libyans were among rebels killed in Aleppo. <em>Caption: In this Sept. 18, 2011 file photo, former rebel fighters celebrate as smoke rises from Bani Walid, Libya, at the northern gate of the town. (AP Photo/Alexandre Meneghini, File)</em>
U.S. officials and others worry that Syria could become a new foothold for insurgents inspired by al-Qaida. Assessing the degree of radical Islamic ideology in the civil war is impossible, but at least one group, the al-Nusra Front, has emerged and declared allegiance to the Free Syrian Army. Al-Nusra, or Victory, has claimed responsibility for several high profile attacks, including a double suicide bombing in March that killed 27 people in Damascus and the execution-style killing of a Syrian television presenter who was abducted in July. On Friday, U.S. intelligence officials said al-Qaida has advanced beyond isolated pockets in Syria and now is building a network of well-organized cells that could include several hundred militants. <em>Caption: This photo shows Al-Qaida's new leader Ayman al-Zawahiri in a still image from a web posting by al-Qaida's media arm, as-Sahab, Wednesday July 27, 2011. Al-Qaida's new leader has lauded protesters in Syria for seeking to topple the regime of President Bashar Assad. (AP Photo/IntelCenter) </em>