The Syrian army stepped up shelling and air strikes on the last rebel-held enclaves in the Syrian capital on Monday, its heaviest bombardment in a two-month campaign, rebels and witnesses said.
From the strategic Qasyoun Heights that overlooks Damascus, elite units of the army pounded Jobar district, some 2 km (1.2 miles) east of the Old City wall and Ain Terma just to the south.
Video uploaded to social media on Monday purported to show the air strikes on the Ain Terma area of the city.
The army's offensive has dented a Russian-sponsored ceasefire announced two weeks ago in the Eastern Ghouta area to the east of Damascus.
Moscow has said it is negotiating with mainstream rebel groups in several areas across Syria to create new de-escalation zones and calm fighting.
Rebels and residents said Moscow had already begun deploying some military police in certain checkpoints that border the rebel-held northern Homs countryside and in southwestern Syria where "de-escalation" zones have been announced.
Residents and rescuers say the Syrian army has intensified shelling of civilian areas in the Eastern Ghouta region where rebels are holed up, many in underground tunnels, out of frustration at the lack of progress.
At least 15 civilians have been killed and scores of others injured in three days of sustained bombardment.
Before the war began in 2011, more than half a million people lived in Eastern Ghouta, a sprawling mix of towns and farmland.
Two residents said Ain Terma was now a ghost town, with only a few hundred families taking shelter in basements after most former residents fled to other towns in Eastern Ghouta.