Fierce clashes broke out in the Syrian capital today after insurgents infiltrated government-held parts of the city through tunnels.
It was a rare if brief advance after months of steady losses at the hands of government forces elsewhere in the country.
It was a surprising breach of Damascus' security perimeter, where the Government has effectively walled itself off from opposition forces encamped in two enclaves in the eastern parts of the city.
President Bashar al-Assad's Government has endeavoured to maintain a veneer of normalcy inside the capital as his forces bomb opposition areas on the edges and suburbs of the city.
Outside Damascus, hundreds of thousands of civilians are living under government siege and bombardment.
Infantry and tank reinforcements arrived on the government side to repel the attack in the afternoon, the group said.Residents said artillery shells and rockets were landing inside the heart of the city, and the activist-run Damascus Today Facebook group reported government air raids over the area of the clashes.
With its military depleted from six years of fighting and defections, the Syrian Government relies on a blend of official and semi-official forces to defend its territory, including Shia militias from Iran, Iraq, Lebanon, and other Middle Eastern countries.
The clashes centered on a government-held gap between two besieged opposition enclaves, the Jobar and Qaboun neighbourhoods. The ultraconservative Ahrar al-Sham rebel faction said fighters had "liberated" the area.
The Levant Liberation Committee - an al-Qaeda-linked group - and the independent Failaq al-Rahman faction also participated in the attack.
Syrian state media said the military had repelled an attack by an al-Qaeda-linked group after "terrorists" infiltrated through tunnels in the middle of the night.
Rebels detonated two large car bombs close to the Jobar neighbourhood. The Levant Liberation Committee claimed the attack.
The Government has been trying to pressure the rebels to surrender the pockets they hold in Damascus following victories in the northern city of Aleppo, the central city of Homs and other Damascus suburbs.
Tens of thousands of fighters, dissidents, and their family members in long-besieged areas have accepted exile to the country's rebel-held northwest, in what opposition figures have termed "forced displacement".
A UN inquiry into the Government's assault on Aleppo last year concluded the regime's siege and punish strategy amounted to a war crime, but the formula continues to produce results.