Literally everybody is pointing fingers at Israel but I haven't seen any news where Israel have come forward to claim that they are the ones responsible for this Hezbollah attack. We know that Israel has existing crisis with this people, but it has not been ascertain that the explosion of gadgets was done by them. However it is of great importance to Note that if not for this explosions, we wouldn't have known that Hezbollah are carrying and walking around with undercover gadgets for communication for which purpose we don't know.
Do you expect Israel to claim responsibility for such a terrorist act? The plan was executed without consideration of the risk it posed to civilians. Most of these explosions happened in public places and at home, and innocent women and children became victims. Israel has a history of keeping silent after carrying out such attacks. The country's spokesman has the tradition of neither declining nor accepting that they are behind an attack.
The conflict is gradually escalating to a full-blown war. Isreal believes that have weakened Hezbollah so that might want to replicate what they did in Gaza. But they might be in for a big surprise.