Fighting and bombardment around Damascus have eased significantly since Russia, Turkey and Iran agreed a deal for "de-escalation zones" around Syria in an April meeting in Astana, Kazakhstan.
Fighting since then has mostly focused on Syria's sprawling desert in the center and east of the country, where warring sides are racing to capture territory from Islamic State.
However, strikes on Thursday targeted the Eastern Ghouta oasis area of farms and towns outside Damascus after at least two shells hit the capital's Qassaa district, the Reuters witness said.
The war monitor, the Syrian Observatory for Human Rights, said rocket and the Syrian army also bombarded the Jobar district in eastern Damascus.
The next round of talks in Astana is likely to be held in early July, Russian media have quoted a senior official as saying. More substantive peace talks in Geneva could resume after that.