It would be the same as launching a missile - the fact that they are being remotely controlled does not seem to be a factor that would diminish personal responsibility (or the chain of commands') nor liability compared to any other form (nor dilute it - even if multiple people are controlling it simultaneously).
The question then becomes whether or not the incidents amount to war crimes, certainly they involve civilian casualties and some of them have reportedly been targeted against political actors considered potential sources of future difficulty as opposed to actually enemies... tbh there are a lot of things done these days that could be called war crimes were they done by other nations but this has been the case ever since the league of nations and will continue so long as there is more than one country.
Personally I think we are at a point historically where we are going to see a flurry of such activities before these technologies begin to be utilised by other nations, in which case as geopolitical realities shift there will suddenly be a 'rethink' and people will have an epiphany that perhaps there should be limits on such means of warfare (which, given it has been used either in breaches of national sovereignty or else in an actual war - is what armed drone use is - while unarmed drone use is arguably merely another spy tool, armed drones could be considered either tools of war or else of assassination, the former being perhaps the more honorable label).
