That's like planting a bomb in front of a military camp. You might have a target, but in the end you just kill whoever was nearby at that time. In the case of the pager attack, that includes children aged 11 and 12, as well as a nurse.
That's much closer to a terrorist attack than to legal warfare.
"planting a bomb in front of a military camp" is like the textbook goal for bomb-planting devices (airplanes, artillery, MRLs), its one of the most normal scenarios out of all of normal war scenarios.
Planting a bomb on each soldier would be even better.
That's much closer to a terrorist attack than to legal warfare.