Rebels battle in heart of Damascus
The monitoring mission's fate is unclear with its mandate expiring in two days. Kofi Annan, the international mediator behind a peace plan, said he was disappointed.
Most attention is now on the streets. Experts say the next few days will be critical in showing how well the government can recover from the double blow of losing its top security officials and their image of untouchable might.
"Everyone is looking now at how well Assad can maintain the command structure. The killings yesterday were a huge blow, but not fatal," said a Western diplomat following Syria.Western officials fear civil war could spill across borders.
Areas of Damascus without fighting were largely deserted. Residents said the roads to many southern districts where fighting was heaviest were closed or peppered with
Syrian TV flashed a warning on its screen, telling residents gunmen disguised in Republican Guard uniforms were spreading through Damascus "planning to commit crimes and attack people".
Activists said real Republican Guard forces were in the Midan district. "We tapped into their walkie-talkies ... we are afraid of a massacre," activist Samir al-Shami
said."Everyone in the neighbourhood is arming themselves. Some with machineguns, some with shotguns. Some even just with
knives," one resident near Midan said.
"I can't even tell you what is going on outside because I've shuttered the windows and
locked the doors. I just hear every now and then the gunfire, it's like it's in the room," said another resident near Midan reached by telephone.
People fleeing violent areas began searching for safe havens, some even taking refuge in the marble courtyards of the ancient Umayyad Mosque in Damascus's historic Old City.
"We tried to find cheap hotels but all of them were full with other people who fled. So we came here to the mosque and said look, we have nowhere to go, nowhere to sleep," one woman in the group told a resident who toured the area,
The bombing yesterday seemed part of a coordinated assault on the capital that has escalated since the start of the week. Rebels call it the "liberation of Damascus" after
months of fierce clashes that activists say have killed 17,000 people.
A security source said the bomber who struck inside the security headquarters was a bodyguard for Mr Assad's inner circle. Anti-Assad groups claimed responsibility.
UN secretary general Ban Ki-moon condemned the Damascus blast and expressed grave concern over the use of heavy weapons.
"Time is of the essence," he said. “The Syrian people have suffered for too long. The bloodshed must end now."
While fighting rages in Damascus, clashes and shelling have also continued elsewhere across the country.Rebels said they had "liberated" the town of Azaz in northern Aleppo province, bordering Turkey.
Activists also published video of the town of Talbiseh, in central Homs province, being sprayed with gunfire from helicopters above.
Fighting also erupted near the Syrian-Israeli frontier, and Israel promptly responded saying it would not accept refugees.
"In the event of the regime's downfall, which could happen... (Israeli forces) here are alert and ready, and if we have to stop waves of refugees, we will stop them," defence minister Ehud Barak said.