Recent Purchase - Nato Aggression Label

Not sure what the full background of this piece is, but just found it interesting enough to spend a buck for it.
This postcard? seems to almost seem to be just a photo copy of a picture of a damaged building on a light card stock. The seller had literally dozens of different scenes (all of bombed buildings), all with the same format on the reverse. I only picked one at random, because my interest is in the label on the reverse.
As I mentioned, they seem to be black/white photo copies, so both the label as well as the small Red Cross emblem are self-adhesive labels attached.
The obverse shows the destroyed fuel depot in Smederevo.

There are different ones around, similarly inscribed, usually with no clues of what side the maker was on (obviously not NATO). Take them as homemade publicity/propaganda postcards. This one was done with some cheap or free graphics program and was probably printed on a home computer printer.

Hope the label is in a mount and not printed like that on the card. The label itself is a rather bad homemade production.