On distinction, Finucane explained that the carriers of the pagers and walkie-talkies would have to be "lawful targets, either on the basis of their status as fighters in an organized armed group that is party to a conflict with the attacker, or due to their direct participation in hostilities."

It is unclear how the attack - which looks to have been highly sophisticated - occurred, though Hezbollah has blamed its adversary Israel. Israeli officials have so far declined to comment. Here is what we know so far.