Unusual Israeli confirmation of military action comes as Syria says most missiles were shot down by its air defences.
Israel was accused on Tuesday of launching a series of attacks on Iran-backed militia targets inside Syria as it reportedly intensifies cross-border raids.
The Syrian army said in a statement Israeli aircraft hit military barracks in al-Safirah in the eastern Aleppo countryside. Earlier, state television said a research centre was targetted. The army said it was now assessing the damage caused by the raids.
The UK-based Syrian Observatory for Human Rights war monitor said air attacks killed 14 Iranian and Iraqi fighters in the desert near the town of Mayadin.
Syrian Observatory head Rami Abdul Rahman said it was “likely” that Israel mounted the operation.
A spokesman for the US-led coalition battling the armed group ISIL (ISIS) said it was not responsible for the air strikes.
Iranian-backed militias and their allies command a significant presence in eastern Syria south of the Euphrates Valley. The region lies close to the Iraqi border.
Israel has launched hundreds of strikes in Syria since the start of the civil war in 2011, targeting government troops, allied Iranian forces, and Hezbollah fighters.
It rarely confirms details of its operations in Syria but says Iran’s presence in support of President Bashar al-Assad is a threat and it will continue its strikes.
An Israeli diplomatic official, who asked that their name be withheld, did not comment on the strikes but said, “Iran was only country still shipping missiles and missiles technologies to their proxies in the region” amid the global health crisis.
A regional intelligence source said Israel was stepping up raids in Syria at a time when world attention and the region, including Syria, were distracted by the coronavirus pandemic.
An Israeli army spokeswoman declined to comment.
Western intelligence sources say Iranian-backed militias have long been entrenched in Aleppo province where they have bases and a command centre and installed advanced weapons, part of a growing presence across government-controlled Syria.
The Scientific Studies and Research Center is one of several facilities where Western intelligence and opposition sources suspect Syria, with the help of Iranian researchers, works on developing chemical weapons they accuse Syria of having used against civilians in rebel-held areas.
Damascus and its ally Moscow deny they have used chemical weapons that have killed hundreds of civilians in the course of the nine-year conflict and blame armed rebels for such attacks.
Commenting on the apparent intensification of Israeli raids, Yoram Schweitzer of Israel’s Institute for National Security Studies, told AFP news agency the Jewish state might be reacting to increased hostile action from Iran and Hezbollah.
It is also possible that Israel is trying to apply added pressure as its rivals endure the fallout of the coronavirus crisis, he said.
“I don’t know which one of the two it is, but might be a combination of the two,” Schweitzer said.
Israeli helicopters fired several rockets from the Israeli-occupied Golan Heights on targets inside southern Syria known to be a base for Lebanon’s Hezbollah militia, Syria and intelligence sources said.
Large blasts in an ammunition depot near Homs city on the same day were also believed to be from an Israeli raid, a war monitor and intelligence sources said.
Israel has acknowledged in recent years it has conducted many raids inside Syria since the start of the civil war in 2011 where it sees Iran’s presence as a strategic threat.
Regional intelligence sources say that Israel’s escalating attacks on Syria are part of a shadow war sanctioned by Washington and part of the anti-Iran policy that has undermined in the last two years Iran’s extensive military power without triggering a significant escalation.
Defence Minister Naftali Bennett told Israeli media last week that Israel would step up its campaign against Iran in Syria.