“28 Israeli F-15 and F-16 aircraft were used in the attack, which released around 60 air-to-ground missiles over various parts of Syria. Israel also fired more than 10 tactical ground-to-ground missiles,” the ministry said in a statement, quoted by Interfax news agency.
The Britain-based Syrian Observatory for Human Rights said at least 23 fighters were killed, including five Syrian regime troops and 18 other allied forces, a monitor said Thursday. The regime troops killed included an officer, adding that the other casualties included Syrians and foreigners.
The scale of Israeli fire was far higher than in previous incidents and Damascus residents described seeing a series of explosions above the city from air defence systems.
Tensions between Israel and Iran have threatened to spill over in Syria, where the Iranian military and allied Shi'ite militia are backing Syrian President Bashar al-Assad in his war against rebels seeking to oust him.
"Air defences confronted tens of Israeli rockets and some of them reached their target and destroyed one of the radar sites," Syrian state news agency SANA reported, citing a military source.
Another rocket hit an ammunition warehouse, it said.
Asked whether Israel had attacked near Damascus or scrambled communications there, an Israeli military spokeswoman said: "I have no comment on that at this time."
Syrian state television was broadcasting footage of its air defences firing at incoming rockets, and playing patriotic songs.
It said Israeli warplanes were firing the rockets from outside Syria's borders and targeting Baath City in Quneitra province.
Israel's military spokesman Lieutenant Colonel Jonathan Conricus said earlier that Israel had retaliated for an attack on its outposts in the strategic Golan Heights plateau. He did not elaborate.
Conricus did however stress that Israel was not seeking an escalation.
Israeli media said residents of Metulla, on the Lebanese border, had been instructed to go to bomb shelters. There was no official confirmation.
Syria's state news agency, SANA, and a war monitor, the Syrian Observatory for Human Rights, had reported artillery fire from Israeli-held territory at Baath City, located near the border.
The Observatory said rockets were fired at military positions of the Syrian army and allied forces.
A correspondent for SANA said strikes were targeting Syrian air defence brigades and attempting to destroy radar installations.
Lebanon's National News Agency, citing Lebanese Army Command, reported Israeli jets circling over Lebanese territory early on Thursday before exiting.
The late-night incident followed a surge in tensions between Israel and Syria, where Iranian and Lebanese Hezbollah forces have been helping Damascus beat back a 7-year-old rebellion.
Israel describes Iran as its biggest threat and Hezbollah as the biggest threat on its borders.
Fearing that Iran and Hezbollah are setting up a Lebanese-Syrian front against it, Israel has occasionally struck at their forces.
Iran blamed it for an April 9 air strike that killed seven of its military personnel in Syria, and vowed revenge.
Conricus said that in Thursday's attack, around 20 projectiles, most likely rockets, were fired by the Quds Force, an external arm of the Iranian Revolutionary Guards Corps, at around 12.10 a.m.
"A few of those rockets were intercepted" by Israel's Iron Dome air defence system, Conricus told reporters. "We are not aware of any casualties. The amount of damage that we currently assess is low."
Asked if Israel retaliated for the salvo, he said: "We have retaliated but I have no further details about this."
Expectations of a regional flare-up were stoked by U.S. President Donald Trump's announcement on Tuesday that he was withdrawing from the Iranian nuclear deal.
Hours later, Israeli rockets targeted a military base in Kisweh, a commander in the pro-Syrian government regional alliance said.
The strike killed 15 people, including eight Iranians, the Observatory said. Israel has neither confirmed nor denied responsibility.
(FRANCE 24 with REUTERS, AFP)