Russians shot down their own Su-34 is newest modification of this model, numbering only 10-12 boards.

The Russian Su-34 bomber shot down by the Russians is the latest modification of this model. There were up to 12 Su-34Ms in total, with the Russian Federation comparing it to the F-35 fifth-generation fighter-bomber developed by the American firm Lockheed Martin.
According to Censor.NЕТ, this is stated in Facebook by Oleksiy Trubnikov who performed a spotting analysis of this aircraft.
He noted: "Interesting details regarding the Russian Su-34 bomber shot down this night in Luhansk region. On the video of the wreckage of the plane you can see the last digits of the registration number RF-***90 and they correspond to only one recorded number for this type of aircraft - RF-95890.
According to the website Scramble.nl, that was the number the Su-34M flew with, the latest modification of that model, of which only 10-12 were produced. The aircraft was based at Khurba airbase as part of the 277th Bomber Aviation Regiment.
It appears that this air regiment was relocated from the Far East to bomb Ukraine's Donbass. However, the Russian air defense, frightened by the use of GMLRS missiles, mistakenly intercepted its own bomber.
The very same bomber they were comparing to the best American planes could do nothing against far from the best air defense systems. Such a thing!"