It said a Syrian surface-to-air missile was sacked in the direction of an open area of the Israeli-occupied Golan Heights but it was unclear if it had hit Israeli-held territory.
Russia's RIA news agency said that Syria's military shot down an Israeli military aircraft, citing a Syrian security source.
"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 of the two main areas struck, including one believed to be an Iranian weapons depot near the capital.
The area where the incident is said to have occurred is where Lebanon's Hezbollah, a group backed by Iran, has its communications and logistics hub for southern Syria near the Israeli border, according to two senior regional intelligence sources.
State media quoted a military source but did not specify what the target was or where it came from.
"A high-ranked Syrian security source in a comment to Sputnik on Friday denied statements about an Israeli combat plane shot down by the Syrian air defense, confirming that Damascus' forces had indeed downed several aerial targets that had attacked the Syrian territory".
'Freakishly Huge' Cow Is Too Large To Be Slaughtered
If he wants to go for a walk, they follow, if he wants to sit down, they wait around for him to get up. But after a few more rotations of cattle, the cattle farmers "realised he wasn't stopping growing".
Abdel Rahman said Thursday was the first time Syria's air defences had been called into action since the September downing and the delivery of advanced new Russian missiles.
The Astana process by Russia, Iran and Turkey to end the Syrian conflict has only led to a "stalemate" in efforts to establish a constitutional committee crucial to a political settlement, the U.S. said on Thursday.
That incident created tensions between Israel and Russian Federation, another Syrian government ally, with Moscow saying it reserved "the right to take commensurate measures in response".
Israel has carried out hundreds of air strikes in neighbouring Syria against what it says are Iranian targets. Hezbollah is an ally of Iran and Syrian President Bashar al-Assad.
Following the incident, Russian Federation sent advanced air defence missiles to Damascus. Operation of the system could thus make Israeli jets far more vulnerable in any future missions in Syria.
Israel's Prime Minister Binyamin Netanyahu told Russian Federation his country would continue to hit hostile targets in Syria to prevent Iran from establishing a military presence across the border.