Genocide =/= war. Stop trying to justify genocidal terrorism on the basis of some imaginary "war".

I think the point was that, for the people around, this was undistinguishable from suicide bombers, which are usually considered as terrorists. Terrorism is meant to inspire terror and insecurity. This did exactly that.

Human Rights Watch called it unlawful:

Customary international humanitarian lawprohibits the use of booby traps – objects that civilians are likely to be attracted to or are associated with normal civilian daily use – precisely to avoid putting civilians at grave risk and produce the devastating scenes that continue to unfold across Lebanon today. The use of an explosive device whose exact location could not be reliably known would be unlawfully indiscriminate, using a means of attack that could not be directed at a specific military target and as a result would strike military targets and civilians without distinction.

There is no "war-zone". There are no "combatants".

There's just genocidal terrorists murdering civilians in several different states.