In the Syrian capital Damascus, the street battles have become stubborn and protracted. In the country's second city, Aleppo, rebel fighters emboldened by the actions of their comrades to the south, rose up yesterday, turning this ancient city located at the crossroads of several trade routes from the second millennium BC into a modern-day killing field.
Among President Bashar al-Assad's inner circle there is uncertainty and with it, a lack of unity as increasing numbers of his once-loyal officers jump ship, defecting to an ever more confident rebel force.
Across the country, ordinary people too sense the bloodiest and bitterest battles for the heart of Syria are now underway with tens of thousands of them on the move seeking safety and sanctuary in neighbouring Lebanon, Iraq and Turkey.
The massive upsurge in violence comes as the UN Security Council struggles to find a diplomatic solution by voting to extend the UN observer mission in Syria for a "final" 30 days.
It is a timescale during which the world body will be hard pressed to contain a situation that will see Assad wrenched from power and in the process possibly unleash a sectarian war that could spill across the Middle East's borders. For if one thing above all else is now glaringly obvious in the Syrian crisis, it is that diplomacy has failed to keep pace with events.
"The regime is going through its last days," Abdelbasset Seida, the leader of the main Syrian opposition umbrella group, the Syrian National Council, said in Rome yesterday, predicting that the worst of the fighting is yet to come.
In the backstreets of Damascus, Aleppo and elsewhere that was evidently true, as army helicopters and tanks aimed rockets, machine guns and mortars at pockets of rebel fighters who have infiltrated both cities in an operation initially dubbed "Damascus Volcano". Across many neighbourhoods, lightly-armed fighters have been moving through the streets on foot and attacking security installations and roadblocks.
"The regime has been rudderless for the last three days. But the aerial and ground bombardment on Damascus and its suburbs shows that it has not lost the striking force and that it is regrouping," confirmed opposition activist Moaz al-Jahhar by phone from Damascus.
While some sections of the city have become ghost towns others are caught in a fearsome crossfire. A resident in the relatively new neighbourhood of Mezzeh, a district of high-rise towers, villas and cactus fields, said helicopters were firing machine guns and rebels were firing back "uselessly" with automatic rifles.
In those areas of Damascus retaken by regime forces, soldiers proudly showed reporters the dead bodies of rebel fighters lying in rubble-strewn streets. The two-day death toll is said to be more than 470 people, marking some of the deadliest of the uprising. The regime, for its part, has deployed overwhelming firepower, often shelling from afar.
"We often make tactical retreats so that there is no face-to-face confrontation," a rebel named Mohammed from the Eagles of Damascus brigade said via Skype. "It's like gang warfare. We pull out so we can hit in a different place or plan an attack on a regime checkpoint."
Like most rebels, his group has only assault rifles and rocket-propelled grenades, but lacks long-range weapons, leaving them helpless against government shelling and helicopter strikes. They also lack ammunition.
"If we had all the ammunition we needed, we would have liberated the capital in two days," he said.
The clashes echoed those seen elsewhere in Syria, including the northern commercial hub of Aleppo. Some of the fiercest fighting was reported in the Salaheddine district and densely-populated, poor neighbourhood of al-Sakhour. "The sound of bombardment has been non-stop since last night. For the first time we feel Aleppo has turned into a battle zone," a housewife said by phone.
An escalation in the fighting in Aleppo would prove another challenge to Assad, still reeling from the assassination of four of his top security officials last week.
The clashes in Aleppo came as UN Secretary General Ban Ki-moon said he was sending his peacekeeping chief Herve Ladsous and top military adviser General Babacar Gaye to Syria to assess the situation. For his part President Assad has not spoken in public since the bomb attack that killed his closest security and intelligence chiefs on Wednesday, among them his brother-in-law.
While the president's whereabouts are unclear, he is rumoured to be in the Syrian port city of Latakia with his family. Maher al-Assad, the president's brother and commander of the Republican Guard and the 4th Armoured Division, is believed to still be in Damascus. Reports that his forces are fighting in the area support these claims, but it is likely that he, too, will retreat to Latakia if government forces fail to regain control of the capital.
According to the independent global intelligence think tank Stratfor, signs are now emerging that the regime's minority Alawite constituency has lost faith in the sustainability of the al-Assads with increasing reports of defectors crossing into Turkey and Lebanon, among them Alawite troops.
Alawites living in the Greater Damascus area are beginning to panic, say Stratfor analysts, now that the route from Damascus to the Alawite strongholds on the northwestern coast are blocked by a number of rebel-controlled checkpoints. The road from Damascus to the coast also traverses Homs, a bastion of Sunni support where Free Syrian Army (FSA) rebel forces are concentrated.
In any post-Assad political transition, many of these individual Alawite regime members could prove crucial in working alongside rebel opposition activists if there is to be any chance of unifying a demographically-split military to stabilise the country and regain control of jihadists mixed in with the insurgents.
For the moment, though, regime and rebel sides are too busy fighting for their respective survival on Syria's streets. Assad may be going but he is not yet gone.
As one rebel activist put it following last Wednesday's bomb strike that killed Assad's defence and security chiefs at their headquarters in Damascus: "Today we cut off the head of the snake, but we still have the tail."