Lebanese caretaker Prime Minister Najib Mikati issued a statement late Tuesday condemning an explosion in the southern suburbs of the capital Beirut, calling it a "new Israeli crime."
The Palestinian resistance group Hamas confirmed the assassination of its deputy chief Saleh Arouri in the blast.
Hamas said two commanders of its armed wing, the Al-Qassam Brigades, were also killed.
Lebanon's official National News Agency earlier reported that Arouri was killed in an Israeli drone strike on a Hamas office in Mecherfeh in southern Beirut. At least six people were killed in the attack.
"This explosion aims to usher Lebanon into a new phase of confrontations following the daily ongoing attacks in the south, which result in a significant number of martyrs and injuries," he added.
"Lebanon is committed to the resolutions of international legitimacy, especially (UN) Resolution 1701,'' he said.
"However, it is Israel that has breached and surpassed the resolution, as it remains unsatisfied with the level of death and destruction. It is evident to all that the decision of war rests in Israel's hands, and it is imperative to restrain and halt its aggression,'' Mikati said.
In this respect, Lebanon intends to file an urgent complaint with the UN Security Council against Israel in light of the attack, the Prime Minister's Office said in a statement.
Lebanon has previously lodged several complaints against Israel in the Security Council, including cases related to targeting journalists in southern Lebanon and the occupying border towns.
