Air strikes on Damascus airport killed seven fighters, a war monitor said Friday.
The air strike, allegedly conducted by Israel, is the latest in a string of attacks targeting Iran's military presence in Syria.
Syrian state media said only that its air defenses intercepted missiles over the capital overnight while Israel did not immediately comment on the strikes.
Israel is routinely accused of firing missiles at what it says are Iranian targets in Syria, where elite Iranian forces and allied militia play a key role.
According to the Syrian Observatory for Human Rights, the strikes launched late Thursday hit military targets in the area of the international airport.
Rami Abdel Rahman, the director of the Britain-based Observatory, said the dead were three Syrian soldiers and four members of Iran's Revolutionary Guard.
A Syrian army source quoted by SANA said the attack took place at 11:45 pm (21:45 GMT), when an AFP correspondent in Damascus heard loud blasts.
"Our air defenses intercepted hostile targets over the skies of Damascus," SANA said.
It said the "missiles were launched from over the occupied Golan Heights"
Several missiles were intercepted before they could reach their targets, said the agency, which rarely admits to casualties among army or Iranian ranks. The Observatory said the targets in the airport area, which has been repeatedly hit in similar strikes, included an arms depot.
The strikes on the airport compound came just after the arrival of a cargo plane, according to Abdel Rahman, who could not specify where the aircraft had flown in from.
He said a vehicle had also been hit on the road towards central Damascus in what seems to have been an attempt to stop a weapons delivery.
SANA released a video of what appeared to be Syrian air defenses firing over Damascus.
Iran has deployed its Islamic Revolution Guard Corps (IRGC) in Syria to support President Bashar al-Assad, who clung on by a thread earlier in the nine-year-old conflict.
It also holds sway over a myriad militia groups whose ranks include fighters from Afghanistan, Iraq, Lebanon and other countries.
The head of the IRGC's elite Quds Force, Qasem Soleimani, was killed in a US drone strike on Baghdad airport at the beginning of this year.
Soleimani was the mastermind of Iran's foreign operations but Iran's forces remain heavily involved in military operations carried out in Syria.