Its hard to for me to consider anyone who does mass murder of innocent people anything but deranged, regardless of any nitpicking on what you want to call a terrorist, where the crimes take place, whether it was considered an "act of war", the religion or motives of the person performing the crimes, etc.
so yeah, could be both...but IMO niggling over the definition of a "terrorist" is a meaningless semantic exercise. These are deranged people, all of them. What is different about them what causes them to be deranged, and whether that is acceptable to you or not. (not directing this at anyone in particular, but towards anyone considering the problem). Of course I don't think anyone but deranged people think that any murdering of innocents is acceptable.