I am, as you well know, considering the recent theatres of war which the Us has been engaged in... of those, the one which seemed most likely to have farmland (as it appears to be - i.e. ploughed, seems a bit rutted) is, IMO Yugoslavia. Tenous, granted, but there is logic.
NB: they may not have been obvious farmers. for one thing, it appears to be nighttime, which isn't particularly popular time for ploughing the fields round my bit.
That open-top truck could, for example be used to transport troops or partisans. Without knowing the origin, I can't pass judgement on the validity of the attack - they could very well have been enemy guerillas meeting up in an isolated region, for example. Or potentially drug dealers, although I'm not sure if Us operations use that level of force (maybe in Columbia)
Regardless, it is somewhat tasteless that someone decided this should be made public.