The Israeli military destroyed a weapons depot in the coastal Syrian city of Jableh on Thursday.
The Syrian Observatory for Human Rights said the attack carried out via drones and warplane missiles leveled the depot and caused massive explosions heard from long distances.
It added that the Syrian air defences and Russian forces responded to the attack within 40 to 50 minutes.
The depot is situated near the Hmeimim Air Base, the largest Russian air base in Syria, located in the northwestern province of Latakia.
No immediate reports of casualties have been reported.
This latest attack followed a series of Israeli airstrikes in Syria this week.
Two Lebanese nationals, including Hassan Jafar Qasir, the son-in-law of late Hezbollah leader, Sayyed Hassan Nasrallah, were killed in an Israeli airstrike on a residence in the Mazzeh Western Villas neighbourhood of Damascus on Wednesday.
