The Israeli military said its air force had struck what it described as Hezbollah targets in Kfar Kila and killed a Hezbollah leader in Deir Siriane.
Hezbollah has fired thousands of rockets and drones at Israel, saying it was acting in solidarity with Hamas, which is also backed by Iran.
Hamas and Iran have accused Israel of assassinating Mr. Haniyeh, but Israel has not publicly taken responsibility for that killing.
Iran, Hezbollah and Hamas have vowed to retaliate against Israel.
For now, the developments appear to have derailed any prospect, however remote, of a cease-fire between Hamas and Israel.
Persons:
Beit Hillel, Deir, Fuad Shukr, Ismail Haniyeh, Shukr, Israel, Mr, Haniyeh
Organizations:
Hezbollah, Hamas, Sunday
Locations:
Israel, Iran, Lebanon, Beit, Kfar Kila, Deir Siriane, Beirut, Tehran, Golan