(The battle happened between Donbas battalion and Vostok battalion on May 23th at Karlovka.)
Have a look at the members of the Donbas battalion as has been presented in the video from VICE News.
Now look at the two bodies from Ukrainians, that has been found at the scene:
Now look at the fighters from Vostok battalion:
Many more can be found here.
Now look at their dead:
Boston battalion Right Sector Nazi... yeah right.
(Notice the Nazi symbols above the wound in his chest.)
This demonstrates how brutal these guys are.
Some people argue that his heart was not cut out, but that it was a wound from shrapnel. This does not explain though why there is blood on the ground AFTER this man has been carried from the battle scene for some time.