Investigations are still ongoing, but from the current situation, all fingers point at Israel. It is possible they got help from her allies to carry out this terrorist act on civilians. However, it is obvious that there was an infiltration of the supply chain of these pagers. Israelis are the main suspects because they have threatened Lebanon and are well-known for such attacks.
We cannot determine for now if it is an attempt by warmongers to destabilise the region for selfish interest because such an operation will be kept secret. There has been no response from the government of Israel about the attack, claiming or denying their involvement. For now, the Lebanese government will have to do a thorough investigation because there might be more attacks since it seems that the enemy has infiltrated some key areas of Lebanon.