The Britain-based watchdog said two children and a man were killed when Mleha just southeast of Damascus was bombarded, and that two rebels battling forces loyal to President Bashar al-Assad were also killed there.
The Observatory relies on a network of activists and medics on the ground in Syria when compiling its reports and death tolls. It said violence nationwide on Friday claimed the lives of 86 people, among them 30 civilians.
Regime artillery also opened up on Beit Sahem south of Damascus, as well as Jdaidet Artuz and Daraya to the southeast, the rights group said on Saturday.
It reported that regime air raids on Rastan in the central province of Homs caused casualties, without giving an immediate toll of the dead and wounded. One rebel was also killed in clashes there, it added.
In the east of the country, a man was killed when artillery pounded Deir Ezzor, the Observatory said.
Among Friday's casualties were nine rebels, eight soldiers and two regime militiamen killed when insurgents overran the key Taftanaz air base in one of their most important military gains to date. Capturing Taftanaz, from which regime forces launched deadly helicopter gunship sorties, eases the pressure on rebels who already control vast swathes of Syria's north and east.
"This is the largest airbase to be seized since the revolt began" nearly 22 months ago, the Observatory's Rami Abdel Rahman told AFP on Friday. Government forces managed to evacuate most of the 60 helicopters deployed there, leaving behind 20 that are no longer serviceable, the Observatory said.
The United Nations says that more than 60,000 people have died in the Syria conflict which began in mid-March 2011 with peaceful protests that quickly erupted into deadly violence in the wake of a harsh regime crackdown.