UKRAINSKA PRAVDA 04.05.2014

Russia is reinforcing its military grouping in Crimea, sending in aircraft and military units.
This information was reported by a Crimean military expert who asked to remain anonymous (Ukrinform). 

“The sky over Crimea was dark from all the aircraft overhead. Such massive transfer of aircraft has not been seen since the German occupation of Crimea in 1941.” noted the expert. According to our source, Russia has transferred several dozen MiG and Su fighters, close to a complete aviation regiment.