Troops waged fierce assaults on rebels around Syria on Thursday, as top Russian and US diplomats failed in talks with the UN peace envoy to reach any "sensational decisions" on ending the conflict.
President Bashar al-Assad's forces shelled Douma and Zabadani to the northeast of the capital and Daraya and Moadamiyet al-Sham to the southwest, official and activist sources said.
As the army escalated its assault on rebel-held Daraya, the scene in August of the single deadliest massacre in Syria's 21-month conflict, additional troops were deployed to the town.
"Syrian army units continued today to pursue terrorists loyal to (the jihadist) Al-Nusra Front, which is part of al-Qaeda, in Daraya," state news agency SANA said.
Citing an unnamed military source, the news agency also said "Daraya will be completely cleansed of terrorists soon".
An opposition activist told AFP over the Internet that the army is advancing little by little into Daraya, although the rebel Free Syrian Army is fighting hard to keep the troops out of the town.
At the same time, there were clashes in Irbin to the east, the Syrian Observatory for Human Rights said.
In the capital itself, security forces swarmed the southern district of Zahra after a car bomb exploded.
State television said "al-Qaeda terrorists exploded a bomb in a car in front of a Red Crescent centre in Damascus, causing one death and major damage".
Damascus province is now a key battlefield, as government troops fight to create a secure perimeter around the capital, analysts say.
The Observatory said the violence had claimed at least 57 people nationwide.
The Britain-based watchdog has tallied more than 42 000 deaths, most of them civilians, since the uprising erupted in March 2011.
In Dublin, talks among US Secretary of State Hillary Clinton, her Russian counterpart Sergei Lavrov and UN peace envoy Lakhdar Brahimi failed to reach any "sensational decisions".
Brahimi said that, during the meeting on the sidelines of an international gathering, all three agreed the situation was "very, very, very bad" in Syria.
Amid fears the 21-month conflict may take a gruesome new turn and see the Syrian regime unleash chemical weapons, the three discussed "how we can work out hopefully a process that will get Syria back from the brink," Brahimi said.
The United States has been calling on Russia for some time to use its leverage with Assad to try to open the way towards a political transition, although Washington has insisted the long-time leader will have to go.
US officials had hoped Lavrov was signalling a new willingness by staunch Damascus ally Moscow, by accepting Brahimi's invitation, to probe ways to bring more pressure to bear on Assad to step down.
Brahimi said afterwards the three agreed to put together a peace process that will be based on a Geneva accord, adopted under the previous joint UN-Arab League envoy Kofi Annan.
Clinton told reporters shortly before the talks: "We have been trying hard to work with Russia to stop the bloodshed in Syria and start a political transition toward a post-Assad Syrian future".
"And we very much support what Lakhdar Brahimi is trying to do. Events on the ground are accelerating and we see that in many different ways," she added.
In London, meanwhile, Europe minister David Lidington said Britain will press its European partners next week to amend the arms embargo on Syria to allow them to provide weapons to rebels fighting the regime.
Brussels agreed late last month to extend its sanctions against Assad's regime, including the arms embargo, for a further three months, after they were due to expire on 30 November.
Having done that, Lidington said in a statement, "we will make fresh arguments in support of amending the arms embargo ahead of the March 2013 deadline in a way that offers sufficient flexibility to increase practical support to the Syrian opposition."
Britain has formally recognised a newly formed opposition bloc as the sole representative of the Syrian people and has been offering practical support, but this cannot include weapons at the moment because of the EU embargo.