BURSTIsrael on Tuesday bombed a building in Beirut and killed a top Hamas official, according to Lebanese news channels.
The alleged assassination killed Saleh al-Arouri, who was the deputy chief of the political bureau for Hamas in Beirut, the capital of Lebanon.
Lebanese state media reported four people were killed in a drone strike in southern Beirut.
The reported bombing would mark the boldest attack in Lebanon yet from Israel, which has traded fire with Lebanese militant and political group Hezbollah since war broke out with Hamas in early October.
The tit-for-tat strikes between Israel and Hezbollah have been deadly but have largely taken place over the border in skirmishes and artillery fire.
But Israel says it is fighting a multi-arena war against Iranian-backed enemies. Both Hezbollah and Hamas are supported by Iran.
Israeli soldiers also carried out a strike in Syria in late December that killed a top Iranian general.