The Lebanese Shia Muslim group Hezbollah has announced that an Israeli forces' attack killed one of its senior commanders on Wednesday.
Hezbollah retaliated by launching rockets toward Israel.
Israel's Defense Minister Yoav Gallant reportedly said Israel will "reach a state of full readiness to take any action required in Lebanon. ...We prefer an arrangement but if reality forces us we will know how to fight."
The situation remains tense, as full-scale clashes between the two sides are feared to erupt.
Israel's military also on Wednesday announced that its attacks "eliminated terrorists" in southern and northern Gaza.