Troops are scanning the area.
Among the targets struck were two Syrian army brigades where Hezbollah is embedded alongside a rocket depot close to its bases near the border with Lebanon, another Syrian army defector in touch with military personnel said.
"Israeli forces bombarded for an hour positions in the southern and southwestern suburbs of Damascus as well as in the south of Syria at the border of Quneitra province", the Observatory's chief Rami Abdel Rahmane said.
Sources in Damascus spoke Thursday about missiles fired on hostile targets over the Kisweh area and of downing them, while Russian sources reported hitting an Israeli warplane.
On Friday, a senior Syrian defense official refuted previous reports of air defense hitting an Israeli plane.
Earlier, a high-ranking Syrian security source told Sputnik the country's air defence forces had downed an Israeli combat aircraft and four missiles over Al Kiswah, a city located to the south of Damascus.
The Israeli military made no comment on the reported strikes, during which Syrian air defences opened fire for the first time since the deadly downing of a Russian transport plane in September, the Syrian Observatory for Human Rights said.
However, speaking to Reuters, an Israeli military spokesman rejected the RIA report as "bogus".
Daredevil: No habrá cuarta temporada! La serie ha sido cancelada
Si ese es el plan y si mantendrán la continuidad de las series y al elenco de los show de Netflix es un misterio por ahora. Las producciones que aún siguen con vida, aunque quizás tengan sus días contados, son "Jessica Jones" y "The Punisher" .
Israel has reportedly carried out airstrikes in Southern Syria targeting Iranian militias, in its first publicised strike since September.
Also on Thursday, the Israeli army said a missile was sacked at the Israeli-occupied, Syrian Golan Heights, but that it remains unclear where the projectile fell, Haaretz reported.
The attacks came after Moscow supplied Damascus last month with an advanced S-300 air defense system, not yet believed to be in use, as Syrians still need to be trained on operating it.
Moscow pinned responsibility for the downing on Israel, saying its fighter jet used the larger Russian one for cover, an allegation Israel disputed.
In 2017, the BBC, quoting a Western intelligence source, reported the Iranian military had a compound outside Al Kisweh.
Iran is a key ally of Syria's Bashar Assad and supports a number of militias that have fought alongside the Syrian army and its allies.
He added that Israel would "continue security coordination" with Russian Federation.