On Friday, a senior Syrian defense official refuted previous reports of air defense hitting an Israeli plane.
"It's bogus", an Israeli military spokesman told Reuters in reference to a Russian RIA news agency report that made the claim.
"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", Observatory chief Rami Abdel Rahman said.
Syrian opposition sources and groups on the ground said the area was close to where the Iranian-backed Lebanese group Hezbollah has a powerful presence with several bases.
State media quoted a military source but did not specify what the target was or where it came from.
Russia's RIA news agency cited a Syrian security source as saying that the "Syrian air defense forces shot down an Israeli war plane and four missiles".
Abdel Rahman said Thursday was the first time Syria's air defences had been called into action since the incident on September 17 in which 15 Russians were killed.
Israel has carried out hundreds of air strikes in neighbouring Syria against what it says are Iranian targets, many of them in the area south of Damascus.
The Syrian foreign ministry has sent a letter to the UN Secretary-General and the president of the UN Security Council containing a blistering criticism of the United States and Israel over their regular aggression inside Syrian territory.
However, a surface-to-air missile was sacked at an open area in the Golan Heights and IDF forces are searching the area for additional hits.
In October, Moscow equipped Damascus with the advanced S-300 surface-to-air missiles, days after Israeli fighter jets attacking Syrian targets used a Russian surveillance plane flying nearby as a shield and misled the Syrian air defenses to shoot it down.
Israeli soldiers were scanning the area, the Israeli newspaper said. "This is just another piece of evidence that Israel supports terrorist groups and is trying to prolong the conflict in Syria".
Russian Federation subsequently upgraded Syrian air defenses with the delivery of the advanced S-300 system, which Damascus had said last month would make Israel "think carefully" before carrying out further air raids.
Israel has repeatedly warned that it will act to prevent Iran from consolidating itself militarily in Syria, and continue to strike weapons convoys en route from Tehran to Hezbollah.