At least nine pro-regime fighters were killed in an overnight strike attributed to Israel in northern Syria, a war monitor reported Monday.
According to the U.K.-based Syrian Observatory for Human Rights, six of the fatalities in the strike were Syrian fighters and the remainder of the casualties were not identified.
In June, The Wall Street Journal reported that Hezbollah terrorists and pro-Iranian militants were fighting in Syria disguised as Syrian soldiers.
The watchdog group also noted that the target of the strike was a military post operated by Iran's Revolutionary Guards.
An official source in Syria accused Israel of perpetrating the strike.
Syrian media reported Monday that Israeli missiles hit a Syrian military position near Nairab airport, on the outskirts of the northern city of Aleppo.
"The Zionist enemy … targeted one of our military sites north of Nairab airport, causing only material damage," the state-run Syrian Arab News Agency quoted a military source as saying.
Other reports suggested that Sunday's attack, which occurred shortly after 10 p.m., targeted an Iranian weapons warehouse and were an attempt by Israel to support rebels in southern Syria, where Syrian government forces have been waging an offensive.
More than 10 missiles were allegedly fired at the airport, to which an Iranian shipment had apparently been delivered. Several Syrian army facilities north of Nairab airport are being used by Hezbollah and Iranian forces.
An Israeli military spokesman declined to comment on the report.
Reports from Lebanon indicated that the target of the strike was actually a structure housing Iranian troops, not a weapons warehouse.
"The Zionist enemy repeated its desperate efforts to support the defeated terrorist groups in Daraa and Quneitra, and launched missiles at one of our military positions north of Nairab airport," a television network affiliated with Hezbollah reported. "The damage was strictly material."
Israel, concerned that Iran's burgeoning presence in Syria poses a threat to its security, has struck dozens of Iranian and Iran-backed positions in Syria over the course of the seven-year conflict in Syria.
Iran is a key ally of Syrian President Bashar Assad and backs a number of militias, including Lebanon's Hezbollah, fighting in support of Assad.
Last Thursday, Israel targeted positions in the southwestern Quneitra province, near its frontier with Syria.
Meanwhile Sunday, Syrian government forces unleashed hundreds of missiles on a rebel-held area near the Israeli border on Sunday, activists said, the latest phase in an offensive to clear southern Syria of insurgents.
The government's push came after it had secured control of most of Daraa province in an offensive that began in June. On Sunday, the first batch of armed fighters and their families left the city of Daraa, the provincial capital, in buses that would take them to the rebel-held Idlib province in the north.
Assad said Sunday the success in driving the opposition out of Daraa embodies the will of his army and allied forces to "liberate all of Syrian territories" of "terrorism."
In recent months, backed by Russian air force, the Syrian government has restored control of over 60% of previously rebel-held territory across the country.
Assad spoke during a meeting on Sunday with visiting Iranian Foreign Ministry official Hossein Jaberi Ansari. Assad's office said the two agreed that the "elimination of terrorism in most of the Syrian territory has laid the most appropriate ground to reach results at the political level" that could put an end to Syria's war.
The statement came a day before U.S. President Donald Trump and Russian President Vladimir Putin were scheduled to meet in Finland. Syria is expected to feature highly on the agenda of this meeting.
