This afternoon (15:00 CET) we’ve tracked an USAF Lockheed U-2S (80-1073) “Dragon Lady” descending to RAF Akrotiri.
The spyplane made, probably, a surveillance mission off (or over?) Syria.
Note that Russia have two important bases in Syria: an airbase in Latakia and a naval base in Tartus.
Russia deployed in Syria also S-400 missile system.