I'm not a historian but isn't there some ambiguity here? If war hadn't already been declared by the relevant governments, you can't be killing in the name of war.
And by the way, when the British seized a Spanish fleet--which had imagined itself to be neutral--during the Napoleonic wars, their government stated that the United Kingdom had never been in the habit of starting wars with a declaration.
* to be done by an individual, not a group
* tends to happen to one, or a few victims. It's odd to describe someone as murdering 70 people at once.
* tends to imply the victim was not professionally engaged in such a way that their death in those circumstances is not a plausible concern
* the motive is not political, else it is an assassination