This blog has now ended, but the Guardian's live coverage is continuing here.

Here's a roundup of the latest developments:

• In the UN security council, Russia and China have vetoed a resolution to impose sanctions on Syria, prompting fierce attacks from the UK and France, who accused Russia of buying time "for the Syrian regime to smash the opposition" (3.58pm).

• Amid speculation regarding President Assad's whereabouts, pictures have now been issued that show him swearing-in the new defence minister. The location appears to be the palace in Damascus (see 4.11pm).

• Rebel forces are beginning to take control of parts of Damascus as law and order breaks down in the city, an activist based in the eastern Mezze neighbourhood told the Guardian (see 3.46pm).

• The Syrian government news agency says Qatar is making models of Syrian cities in order to create fake videos (see 12.43pm). State television has also warned that men in Republican Guard uniforms may be rebels in disguise (see 12.03pm).

Egypt

• The Mubarak regime's former intelligence chief, Omar Suleiman, died this morning in a hospital in the US. He was 76.

Rebels now appear to control a Syrian-Turkey border crossing in Idlib province.

The video above shows one of the rebels destroying a giant portrait of President Assad on the roof of the checkpoint.

A Damascus resident who lives close to the scene of yesterday's attack said he heard three small explosions and witnessed the panic afterwards.

Majd Arar, an activist from the northern district of Malki, lives within five minutes walk of the government building where three of Assad's ministers were killed. "I heard three small explosions, nothing more. It was not too big, he told the Guardian via Skype. He added:

The place I am living in is just like a fortress. I'm near the hospital where the top generals are lying dead now. This place is heavily secured now. I witnessed the ambulances entering the hospitals. After that I saw many doctors rushing away to the hospital. The place was closed down. Every road leading to the hospital was closed. Many officials, it seemed, went to the hospital, because many shaded cars arrived with security guarding it. I think bombs were planted inside the conference room where the generals were meeting.

Since the attacks he said the Free Syrian Army and the government has been competing for control in some neighbourhoods of the city.



The FSA can move freely [in some areas] but the government can, at any time, use tanks to enter those neighbourhoods. The neighbourhoods we are talking about are Midan, Kafr Souseh, Tadamon and part of Yarmouk Palestinian camp ... Every thing has changed now. There's very light traffic, no pedestrians. The markets in the centre are closed. There are very long queues in bread shops. There is no gasoline in the petrol stations. Also garbage is everywhere, because it seem those responsible are not working today. People are scared now ... everyone is expecting something and we're waiting. The place where I live is relatively calm. They are not leaving. Some in the south are coming to the north because it is relatively safer. Nothing is clear now. We are waiting to see how the regime will react to the killing of these top generals, but we expect more fighting.

The way state TV reported the the killings was "odd" Arar said.

Maybe they wanted to conceal something else. We know that this cell responsible for managing the country consists of 12 people. They have announced the death of three people, and two others are heavily injured. We don't know the whereabouts of the rest of the people. Maybe the government is trying to cover up in some way.

The editor of the Jordan Times tweets that Royal Jordanian airline is suspending flights to Damascus and Aleppo.

The first glimpse of Assad since yesterday's attack. It appears that he is indeed at his palace in Damascus.

the syrian tv just aired footage of Assad's meeting with the Defence minister today in the presidential palace #SYRIA #BREAKING — Ali Hashem علي هاشم (@alihashem_tv) July 19, 2012

To all those who said #Assad fled, here's the new defence minister swearing the oath infront of #Syria's president. twitter.com/Hey_Joud/statu… — Joud(@Hey_Joud) July 19, 2012

Adam Gabbatt has been monitoring the UN security council meeting. He writes:

Russia and China have voted against the UN Security Council's draft resolution to impose sanctions on Syria, prompting fierce attacks from the UK and France, who accused Russia of buying time "for the Syrian regime to smash the opposition". Both Russia and China have consistently resisted the council's attempts to introduce sanctions, meaning their veto was no surprise, but the strength of the response from those in favour gave some indication of the frustrations behind the scenes. The UK ambassador, Sir Mark Lyall Grant, was the first to respond to the vote, telling council members that the UK "is appalled by the decision of Russia and China to veto this draft resolution". "Russia and China are failing in their responsibilities as permanent security council members," Lyall Grant said, adding that the proposed resolution is supported by almost every group internationally. Lyall Grant said the other UN Security Council nations had "offered flexibility on Russia and China's concerns", yet the countries "argued that a chapter 7 resolution is somehow designed to seek conflict through the backdoor". "This argument is irrational," he added. The French ambassador, Gérard Araud, was even more criticial, declaring that "'history will prove [Russia and China] wrong, and it will judge them". "It is now clear that Russia merely wants to win time for the Syrian regime to smash the opposition," he said.

"Where is Assad?" (continued):

"[Assad] is in the presidential palace in Damascus with his staff and is directing the destiny of the country," said a close aide, to AFP — AJELive (@AJELive) July 19, 2012

Rebel forces are beginning to take control of parts of Damascus as law and order breaks down in the city, an activist based in the eastern Mezze neighbourhood told the Guardian.

'Omar Daimashki', said he had witnessed three tanks being destroyed by the Free Syria Army in an area that houses eight intelligence buildings.

Omar, a spokesman for the Revolution Leadership Council of Damascus, said the Free Syrian Army had taken control of the neighbourhoods of Midan and Qaboun. They were also fighting for control of Kafr Souseh and Mezze, he claimed.

Usually we have policemen in the street. Usually we feel that the regime is here, yesterday and today we don't feel the regime is here anymore ... They do not control Midan. There is no security in Midan ... I saw tanks in Kafr Souseh, very close to the security building - it is the most important intelligence building - and the Free Syrian Army destroyed three tanks around it.

They were destroyed using RPGs he claimed. One of the tanks was near the Sham central mound close to a security building, another was on Kafr Souseh square, he said. The FSA do not control tanks, but they did seize an armed vehicle, he said.

Omar said fighting has broken out all over Damascus since midnight, with the fiercest clashes have been in Mezzeh and Kafr Souseh.

In Kafr Souseh the clashes were very close to the prime minister's main building, and to the military intelligence buildings. It is a very secure area, but after the explosions in Rawdah [which killed three senior figures], we really feel that we are not facing a regime any more. We are facing some gangs and some murderers.

Regime supporters took to a street called al-Mezzeh 8 and began attacking people, he claimed. Twelve people were killed in the al-Qassaa area, by "Assad militia snipers". A funeral of those killed was then attacked by a helicopter.

We have reporters all over Damascus - some of us are very close to the clashes. I was very close to the clashes and had to change my [location]. All the people in Damascus can hear the clashes.

But in the the last hour it has been more quiet, he said. All the shops are closed apart from bakeries and grocers Omar claimed - a point made by other activists.

It is very different [since yesterday's attack]. We don't feel there is a regime. The government buildings are empty. We don't have policemen on the streets. Only a sniper on the roof guards some buildings. There is no movement in the street. The places are empty. In some places the [humanitarian] situation is very bad. We had more than 15,000 emigrate from the neighbourhoods. They left with only their clothes, because the place is under heavy attack by helicopter. They are shooting everything that moves. The situation has changed very much, but we feel it is going to our side. Now the weak side is the government side.

Russia and China have again used their veto to block a UN security council resolution on Syria. This means the observer mission will not continue.

Tunisia: A military court sentenced ousted president Zine al-Abidine Ben Ali's interior minister and 38 other security officials to up to 20 years jail today in connection with the deaths of protesters during the revolution that launched the Arab Spring.

Reuters reports that former interior minister Rafik Belhaj Kacem was sentenced to 15 years in jail and Ben Ali's security chief Ali Seriati was given 20 years over the killing of protesters in the capital Tunis and the towns of Sousse, Nabeul, Bizerte and Zaghouan as a popular uprising spread through the country early last year.

The court also sentenced Ben Ali to life imprisonment in absentia. He fled to Saudi Arabia as protests swept Tunisia in January last year and is unlikely to be extradited.

Ahmed Friaa, who was named interior minister shortly before Ben Ali fled, was among three officials who had charges against them dropped.

Many of the officials on trial have already been given jail sentences for various crimes linked to last year's revolution.

Syrian state TC says the new defence minister has taken his oath of office in front of President Assad. The announcement did not specify exactly where the swearing-in took place – adding fuel to speculation regarding the president's whereabouts. As yet, no photographs of the ceremony have been released.

General Fahad Jassim al-Freij was named yesterday as the new defence minister following the assassination of General Dawoud Rajha.

Ahead of today's vote at the UN security council, the Guardian's Moscow correspondent Miriam Elder explains Russia's determination to avoid a repeat of the kind of intervention that the UN allowed in Libya.

Speaking to Bloggingheads as news broke of yesterday's of the assassinations, Miriam said: "Russia is just fundamentally against foreign intervention and regime change."

She said the driving force behind Russia's policy towards Syria was not arms sales or its naval base of Tartus, but what happened in Libya.

They are very scared of the same thing happening in Syria, so they are blocking any resolution that does not include language explicitly ruling out some kind of intervention.

Russia's foreign minister Sergei Lavrov has dismissed as a "joke" claims that Assad's wife Asma has fled to Moscow, RIA Novosti reports.

An aide to president Vladimir Putin also denied that Russia had offer to provide a safe haven to members of the embattled regime.

Syria's ambassador to Russia has also denied the Asma rumour, according to the BBC's Cara Swift, citing Interfax.

#Syria ambassador to #Russia denies Asma #Assad is in Moscow & says as far as he knows #Bashar is still in #Damascus. (Source Interfax) — Cara Swift (@cswift2) July 19, 2012

Here's a roundup of the latest developments:

• Clashes continue in Damascus. This morning, people were reported fleeing the Mezzeh area, home to a number of government buildings (see 11.16am).

• The head of UN monitoring mission, Major General Robert Mood, has announced his departure from Syria with a plea for united action at the security council to end the escalating violence in the country. The mandate of the current mission expires tomorrow (see 9.53am)

• British prime minister David Cameron has urged Assad to step down to avert Syria's descent into civil war. Speaking on a visit to Kabul, the prime minister, said that a civil war was inevitable if Assad did not heed the call.

• Syrian President Bashar al-Assad is in the coastal city of Latakia, directing a response to the assassination of three of his most senior henchmen, opposition sources and a Western diplomat told Reuters. Assad has not made a public appearance since Wednesday's attack.

• The Syrian government news agency says Qatar is making models of Syrian cities in order to create fake videos (see 12.43pm). State television has also warned that men in Republican Guard uniforms may be rebels in disguise (see 12.03pm).

• A UN security council vote on Syria has been postponed until later today following a request from international envoy Kofi Annan.

Egypt

• The Mubarak regime's former intelligence chief, Omar Suleiman, died this morning in a hospital in the US. He was 76.

Jordan's King Abdullah has described the killing of Assad's ministers as a "tremendous blow" to the regime.

But in an interview with CNN he said he expected the Syrian government to show "fortitude" following the attack and expressed fears of a civil war.

It quoted the king saying:

This was a tremendous blow to the regime but again, Damascus has shown its resilience, so I think maybe we need to keep this in perspective. Although this is a blow, I'm sure the regime will continue to show fortitude at least in the near future. If it breaks down, if civil order breaks down to the point of no return, it will take years to fix Syria. I have a feeling we're seeing the signs of that. The only people that can bring us back from that brink is the president and the regime. This is the last chance they have.

Assad's forces have been routed from the opposition stronghold of Azzaz, close to the Turkish border, according to video from activists.

A battle for the town, involving tanks and helicopters, has raged for almost three weeks.

Turkish journalist Memet Aksakal, who has been reporting from nearby Killis, told the Guardian that Azzaz has effectively been under the control of the Free Syrian Army for the last two weeks. He said:

Inside Azzaz there was only one building where Assad's forces were based. They never left the building.

Remember those claims that the fall of Colonel Gaddafi's regime was just a hoax staged on a film set in Qatar? The Assad regime seems to think the Qataris have similar plans for Syria. Sana, the government news agency, reports:

A security company in Qatar specialised in manufacturing models has started executive preparations in a move that is aimed at misleading the public opinion about what is going on in Syria. According to special sources, the company has manufactured models analogous to official buildings and squares in Damascus, Aleppo and Lattakia in al-Zoubareh region near Doha. The sources quoted eye witnesses as saying that the company started gathering people to make them wear special customs [sic] to represent military personnel and photographers as if from the Syrian TV channels and prepared public, private and military cars with fake Syrian registration plates to film fake videos and fabricated photos about the situation in Syria.

In Beirut, Guardian reporter Luke Harding has been talking to influential columnist Rami Khouri, who today described the Assad regime as a "dead duck".

Khouri told him the government in Damascus is likely to survive for "no more than a couple of months", with the Syrian conflict now "speeded up" following yesterday's devastating Damascus bombing: "There is no other direction now than the collapse of the regime. Once the essential confidence of the people holding it up starts to shake the final collapse is very close," he said.

Khouri added that the circumstances of the bombing are murky, amid reports from neighbours that the national security headquarters in the capital where the blast allegedly went off appears undamaged.

"Is it an inside job? Or a palace coup that went wrong? We don't know. The problem is that this regime is very secretive," he said. "What we know is that the ability of this regime to govern has gone."

Assad's only remaining option is to flee the country, Khouri said – pointing out that this option is still eminently viable, since there is currently no international indictment against Syria's president.

"He [Assad] has lost the reform option. He has lost the dialogue option. The violence option has proved futile. His only option now is to get out of the country safely. He could still retire somewhere," he said.

There should be a UN presence in Syria, but only if both sides commit to a political process, Major General Robert Mood, the outgoing head of the UN's monitoring mission, told reporters in Damascus.

The UN has released footage of his last press conference.

In questions after his statement (see 9.53am) he said:

The value of the unarmed observer mission is that we can be extremely helpful when the parties decide to use that tool ... Three hundred observers cannot stop the violence. We are not going to be able to impose on these players. But once the political process starts the tool is effective. We have proven its value.

In his statement Mood condemned yesterday's attack. In an answer to a question he added:

We are seeing an escalation, and we are seeing that high value targets [are] being directly attacked in the heart of Damascus. In terms of lives there is no difference between those killed in Damascus and those who have been killed for a long time in other cities.

Syrian state television has issued a warning that gunmen are planning to attack people in the capital using military uniforms as disguises, Reuters reports.

"Armed men in Tadamon, Midan, Qaa and Nahr Aisha (neighbourhoods) are wearing military uniforms with the insignia of the Republican Guard. This confirms they are planning to commit crimes and attack people, exploiting the trust of citizens in our courageous armed forces," Syria's official channel said in a message flashed across the screen.

Activist Alexander Page gave this response:

#Syria'n state tv accusing FSA of disguising themselves as presidential guard (so now when they perform massacres they will just blame FSA) — Alexander Page (@AlexanderPageSY) July 19, 2012

The Spanish civil war of 1936-39 holds lessons for western governments regarding the conflict in Syria, Robert Springborg, a professor of national security affairs at the US Naval Postgraduate School, argues in a letter to the Financial Times (subscription).

Springborg blames the Fascists' success in Spain on western democracies' reluctance to back the Republicans – partly because of fears about communists within their ranks.

The west's hesitancy to back the Syrian opposition is based on similar misguided motives. Anti-government forces are seen as being infiltrated or even dominated by Islamists. Bashar al-Assad's regime is seen as being secular, preferable to that of his father's, and is given credit for having maintained peace with Israel. Russia's assistance in pressurising Iran, permitting resupply of allied forces in Afghanistan and providing energy to Europe, is feared to be jeopardised were Nato to stand up to its provocations in Syria. Analogous causes of western democracies' failures to confront authoritarianism in Spain and Syria may be paralleled by analogous consequences in the latter.

Egypt: Following the death of former intelligence chief Omar Suleiman we're reminded that the New Yorker published a profile of him last year, at a time when he was still considered a possible successor to Hosni Mubarak. Jane Mayer wrote:

Suleiman is a well-known quantity in Washington. Suave, sophisticated, and fluent in English, he has served for years as the main conduit between the United States and Mubarak. While he has a reputation for loyalty and effectiveness, he also carries some controversial baggage from the standpoint of those looking for a clean slate on human rights. As I described in my book, The Dark Side, since 1993 Suleiman has headed the feared Egyptian general intelligence service. In that capacity, he was the CIA's point man in Egypt for renditions—the covert program in which the CIA snatched terror suspects from around the world and returned them to Egypt and elsewhere for interrogation, often under brutal circumstances.

Thanks to EAWorldView for pointing this out.

People are fleeing the Mezzeh area - home to a number of government buildings - after several reports of clashes this morning.

The British-based Syrian Observatory for Human Rights posted this update:

The Basateen al-Mezzeh area is witnessing a large-scale migration out of the area, they are fearing military operations from the Syrian forces who have surrounded the area. Clashes between rebel battalions and regime forces took place in the area in Basateen al-Mezzeh at dawn when regime forces attempted to storm the area. A helicopter was hit during the attack, 3 heavy military vehicles destroyed, 5 regular soldiers killed. Rockets and military helicopters were used in the attack.

New video showed smoke rising above the Mezzeh skyline.

Residents confirmed to Reuters that people are trying to flee the area:

"The refugees have nowhere to go. There is fighting across Damascus," said a housewife watching the fighting from a tower block on Mezze Autostrade near the prime minister's office. Fighting has been focused in the southern and north-eastern suburbs of the city, as well as the central areas of Mezze and Kafar Souseh where several security sites are located. Other parts of central Damascus were quiet on Thursday. Another resident said army snipers were deployed on rooftops in Mezze and Kafar Souseh after rebels attacked armoured vehicles stationed near the prime minister's office and a roadblock erected in the last few days behind the Iranian embassy. "The snipers are shooting at anyone in the streets. Mezze streets are deserted," he said, speaking by phone. Fighting was also reported in Midan, a central Sunni Muslim district where rebels have been operating in alleyways and narrow streets that cannot be entered easily by tanks. Witnesses also said armoured vehicles entered the Sinaa neighbourhood, which is adjacent to the historic Old City centre of the ancient capital.

The "Where is Assad?" guessing game is now well under way. Following Reuters' report that the Syrian president is in Latakia, the Italian AGI news agency says he is still in Damascus: "An official source reported that he has gone to his office to plan the government's response following the attack against the country's defence chiefs."

There's scepticisim on Twitter about the reports:

the "Bashar went to Lattakia" rumor is another version of "Gaddafi fled to venzuela" .. I can c light @ the end of the tunnel ya #Syria — Fadwá El-Gallal (@Douuu) July 19, 2012

The opposition has started pushing Assad to appear on TV by reports through Reuters saying he is in Latakia reuters.com/article/2012/0… #Syria — Zaid Benjamin (@zaidbenjamin) July 19, 2012

Wherever he is, exiled activist Ammar Abdulhamid advises caution, "because a wounded lion is a dangerous animal". ("Assad" is the Arabic word for lion).

Egypt: The Mubarak regime's former intelligence chief, Omar Suleiman, died this morning in a hospital in the US, Egypt's state-run news agency reports. He was 76.

Suleiman briefly served as vice-president during the last days of Mubarak's rule. He also sought to contest the recent presidential election but his candidacy was ruled out of order.

The head of UN monitoring mission, Major General Robert Mood, has announced his departure from Syria with a plea for united action at the security council to end the escalating violence in the country.

The mandate of the current mission expires tomorrow. Mood's statement to reporters suggested he will not lead the mission even if its mandate is extended.

He also condemned yesterday's attack and urged both the government and opposition forces to compromise.

It pains me to say, but we are not on the track for peace in Syria and the escalations we have witnessed in Damascus over the past few days is a testimony to that. I extend my profound condolences and my heartfelt sympathies to the families of all the victims and to the wounded in Wednesday's bombings. I expressed my condemnation of the attack yesterday to the Syria government. I call on the Parties to the end the bloodshed, and violence in all its forms, and recommit to a peaceful solution to this conflict. As you all know too well, the current mandate of Unsmis expires on 20 July. As a result, my duties as Head of Unsmis also expire in a few days. That does not mean that my affections to Syria end today. My love for the people of this country and my desire for them to regain peace are endless. I leave satisfied that I, and some 400 brave women and men, have done our best, under very challenging circumstances. We shifted our posture more than once to accommodate the changes in the security situation, yet still maintain the ability to intervene whenever possible. But the mandate of Unsmis will become relevant when the political process takes off. That is why any extension of the mission would come with a shift to a more political posture. It is the security council that decides the fate of Unsmis and the UN political and military presence in Syria. It is no secret that its members are divided on what actions are needed to end the killing and begin a political transition process. For the sake of the Syrian people we need effective leadership from the security council and genuine unity around a political plan that meets the aspirations of the Syrian people and that is accepted by the parties. Government and opposition must be willing to make the necessary concessions and sit at the negotiating table. If this happens, the presence of the mission (or: a UN political-military presence), Unsmis, will be credible and the mission can contribute to improving the situation of the ground. Let me end by saying that there is no lasting hope in the military solution. I, as a soldier, know more than many, that the decision in favour of peace, is harder than that of war. But I have learned through many years of military practice that it is still better to make that hard choice; to choose peace, even if you can win the war. For it is the fabric of a society that will be deeply damaged by war, and greatly enhanced by the prevalence of peace.

Israeli defence minister Ehud Barak says Israel will stop Syrian refugees from entering the Israeli-controlled Golan Heights if they try to flee there. AP reports.

Barak told reporters after touring the Golan on Thursday that Syrian refugees, who have already started fleeing to Turkey and Jordan, might also start fleeing toward the Israeli-held territory. He added: "If we have to stop waves of refugees we will stop them."

There is a mixture of fear and happiness in Damascus, according to Ameer an activist from the northern suburb of Barzeh.

Happiness because of what happened yesterday and the FSA [being] on the gates of Damascus. And fear of what the upcoming days will bring.

Speaking via Skype claimed there are signs that people are beginning to hoard food amid fears of reprisals.

There are long lines in front of the bakery and food markets ... people want to buy lots of bread because they fear the upcoming days.

There are also concerns about reports of chemical weapons being mobilised, he said.

"I'm scared for the safety of my family," he said.

Ameer recounted the sound of shelling since dawn this morning.

"Every neighbourhood has its own helicopter over it," he said.

The areas of Kafr Souseh and Midan have been under particularly heavy bombardment, he said. But in Brazeh he said shelling had not been as intense and that the Free Syrian Army was making "some progress" in the area. "Yesterday they attacked a security branch, and I think they hit the electricity supply to it," he said.

In nearby neighbourhoods rebels had attacked police stations, he claimed.

Ameer took part in private celebrations after the deaths of three of Assad's inner circle were announced.

We were celebrating yesterday because of the great news of the killing of military figures and the brother-in-law of the president. People were very happy. It was great news yesterday - these people are the regime - they [were] controlled security and the military. Their deaths are great news to us.

According to some rumours Assad was also wounded in yesterday's attack, he said.

Ameer was suspicious of the way the attack was reported on state TV.

Unlike previous terrorist attacks in Damascus there was no television footage of the location of the reported blast, he pointed out.

This time we didn't get any pictures from the location of the explosion. A friend of mine lives near that location and he didn't hear anything. I have no solid report [of how the minister were killed]. I think there are millions of scenarios. I think this was the first time we heard the names of these people on TV. People like Assef Shawkat were like ghosts. No one dared say their names and they are dead now.

Government forces are shelling a number of neighbourhoods in and around the capital Damascus this morning, AP reports citing anti-regime activists.

The Britain-based Syrian Observatory for Human Rights reported shelling in number of areas Thursday. It says residents are fleeing parts of the Mezzeh neighbourhood after troops surrounded it and clashed with local rebels. The group says rebels damaged one helicopter and disabled three military vehicles.

It adds that following yesterday's bombing the whereabouts of President Assad, his wife and his three young children remain unknown.

Damascus - Zamalkeh :: Reports of rocket shelling of the city with helicopters since this morning.#Syria — أخبار الثورة السورية (@NewsSyRev) July 19, 2012

Hezbollah leader Hassan Nasrallah has offered condolences over the assassinations in Damascus yesterday. In a speech to mark the anniversary of the 2006 war with Israel, he said:

"We are sad over the killing of the three because they were comrades-in-arms to the resistance and comrades in the [struggle] against the enemy," – adding: "Israel is happy today because there are pillars in the Syrian army that have been targeted and killed."

The Beirut Daily Star reports:

He reiterated his call for dialogue between the regime and opposition groups to solve the crisis in Syria. "We renew our call for the protection of Syria, its people and army. The only solution is through the acceptance of dialogue and this should be done swiftly," Nasrallah said. He voiced confidence that the Syrian army wound stand fast in the face of armed rebel and opposition groups seeking to topple the Assad regime. "We are confident that the Syrian army, which has had to cope with the intolerable, has the ability, determination and resolve to endure and foil the enemies' hopes," Nasrallah added.

Observers are predicting increased political problems for Hezbollah in Lebanon because of its close ties with the Syrian regime. In an article for Foreign Affairs, Mona Yacoubian explains:

Hezbollah faces a moment of reckoning. The increasingly likely demise of Bashar al-Assad's regime in Damascus would deprive the militant Lebanese Shia organisation of one of its main patrons and could constrain its ability to play an active role in regional politics. Moreover, by offering up unbridled support for Syria, Hezbollah has placed itself at odds with the popular revolts that are unseating autocratic rulers across the Arab world, undermining the narratives of resistance and justice for the oppressed that it has long espoused. Facing the loss of a key ally and with its credibility compromised, an off-balance Hezbollah could turn inward, deepening its involvement in Lebanese politics in order to consolidate its power.

Frank Gardner of the BBC tweets that £100m of the regime's assets have been frozen in Britain. He's promising more details shortly.

BBC learns that £100m of #Syria regime assets found and frozen in UK, part of EU sanctions on 129 individs, 49 entities. My report to follow — Frank Gardner (@FrankRGardner) July 19, 2012

(all times BST) Welcome to Middle East Live.

Here's a roundup of the latest on Syria:

• Syrian President Bashar al-Assad is in the coastal city of Latakia, directing a response to the assassination of three of his most senior henchmen, opposition sources and a Western diplomat told Reuters. Assad, who has not made a public appearance since Wednesday's attack was commanding the government operation, they said. It was not clear whether Assad travelled to the Mediterranean sea resort before or after the attack.

• David Cameron has urged Assad to step down to avert Syria's descent into civil war. Speaking on a visit to Kabul, the prime minister, said that a civil war was inevitable if Assad did not heed the call.

• The state news agency, Sana, has confirmed the death of three members of Assad's inner circle: Dawoud Rajha, the defence minister; Asef Shawkat, the assistant vice president; and Hassan Turkmani, the crisis management chief. It has no word on the condition of the interior minister Mohammad Shaar, who state TV reported killed yesterday.

• The killings put the Syria's uprising into uncharted territory.

Mass defections of soldiers and a rampage by pro-regime militiamen were reported in the capital amid a swirl of rumours, including one that Assad's wife, Asma, had fled to Russia and another that troops were being issued with gas masks, raising fears of the use of chemical weapons.

• President Barack Obama called Russia's president Vladimir Putin today to discuss the crisis after the White House warned that the situation was spinning out of control. The White House said Putin agreed on to support a political transition. Earlier, White House spokesman Tommy Vietor said: "It's clear that the Assad regime is losing control of Syria. There is real momentum against Assad, with increasing defections, and a strengthened and more united opposition that is operating across the country."

• The Obama administration is working on contingency plans for a collapse of the Syrian government, focusing particularly on the chemical weapons that the Assad regime could try to use on opposition forces and civilians, the New York Times reports. Pentagon officials were in talks with Israeli defense officials about whether Israel might move to destroy Syrian weapons facilities, two administration official said without advocating such an attack.

• A UN security council vote on Syria has been postponed until later today following a request from international envoy Kofi Annan. The council is due to vote on a UK drafted resolution that threatens sanctions against the Assad regime under chapter 7 of the UN charter. Russia has indicated that it will veto the resolution. UN secretary general Ban Ki-moon and Annan called on the security council to take strong action on Syria.

• Is the murder of the Syrian strongmen the beginning of the end? Martin Chulov warns it could be the start of something far worse.

Whether the fear factor has been broken will be decisive. Have the opposition's gains galvanised waverers in the regime to join them? Does the regime still have the capacity to shut down violence with overwhelming force? Does it have a new crew of leaders who can command the same loyalty and instil the same fear? Despite Wednesday's tumultuous events, the key items on the opposition's wish list – defections and weapons re-supplies – have not until this point given them a critical mass. And despite yesterday's setback, reprisals and a counterattack by the regime still do seem inevitable.

• "The opposition has hit the jackpot," according to Nadim Shehadi, a Middle East analyst at the thinktank Chatham House in London.