Rebels launched an offensive on the weekend that brought them close to the heart of the Old City of Damascus. Regime forces say they have recaptured ground they lost, but a war monitor said heavy clashes were continuing.
The Turkey-backed Free Syrian Army (FSA) launched an offensive on Sunday that broke a four-year regime siege in the east of the capital Damascus. Late on Sunday, the FSA said its forces had taken control of three villages.
However, the regime said on Monday it had retaken all the ground it had lost, as heavy clashes continued in Damascus on Monday morning, according to a war monitor.
The rebel offensive brought them close to the heart of the Old City of Damascus. The regime responded with intense bombardment of rebel-held areas.
The escalation, reported by witnesses, pro-regime media, rebel sources, and a monitoring group, marked a bid by the rebels to relieve regime pressure on besieged areas rebels control to the east of the capital, a commander from the Failaq al Rahman group which is fighting there said on Sunday.
As the offensive progressed, the FSA tweeted that it had joined the territories of Qaboun, Barzeh, and Teshreen to Jobar, some 2 kilometres east of Damascus.
British-based war monitor, Syrian Observatory for Human Rights (SOHR), on Monday said heavy fighting continued around the Jobar and Qaboun districts.
Regime leader Bashar al Assad and his army, along with allied Russian, Iranian and Shiite militia forces, have put rebels on the back foot with a steady succession of military victories over the past 18 months, including around Damascus. In December, the regime retook Aleppo, Syria's largest city before the war started in 2011.
Since then, the regime has been trying to break down rebel resistance in Damascus and reassert full control of the capital after six years of fighting.
TRT World's Ediz Tiyansan has more on the offensive from the city of Gaziantep on Turkey's border with Syria.