Residents cited by local media reported that the attack lasted nearly an hour and 50 minutes, being considered the most violent and massive in the region in recent years.
Pantsir S1 and Buk systems were employed to repel the attack, shooting down at least 50 hostile air objects.
Footage posted on social networks show explosions near the Russian enclave, while an ammunition depot went up in flames.
The Syrian and Russian authorities have not issued an official statement on the attack or whether there were victims.
The base was attacked on several occasions with drones and missiles launched from the Idlib province, home to the largest remaining terrorist stronghold in Syria.
The information released is contradictory as to whether the attack was carried out by Israel or by terrorists.
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