UPDATE: The Russian military says that a UAV was intercepted.
On May 21, Russian air defense systems, allegedly a Pantsir-S short to medium range system, launched at least four missiles at “unidentified” targets over the Khmeimim air base in Syria, according to local sources.
According to some sources, the missiles intercepted unmanned aerial vehicles (UAVs) launched by militants. The number of the intercepted UAVs is unknown.
Previously, Russian forces interceped two UAVs armed with projectiles on April 24.