Israeli artillery fired at targets in South Lebanon on Wednesday, after a barrage of rockets was launched on Israel in the third such attack in less than a week.
There were no immediate reports of injuries in Israel, the country's Magen David Adom ambulance service said.
No group has so far taken responsibility.
“Four rockets were fired from Lebanon on Northern Israel before the Israeli responded with artillery on the firing sites”.
The Israeli military said its Iron Dome system had intercepted one of the rockets, whilst the other three had fallen without causing casualty.
The Israeli military also said warning sirens were continuing to sound in the Lower Galilee and Krayot area.
Video posted to social media indicate that the rockets had originated in the town of Siddiqin.
A spokesperson for the group Hezbollah declined to comment on the incident.
The Lebanese Army told The National that the rockets were fired with timer devices, and that one unlaunched projectile was discovered. The Army said they had increased patrols to investigate the incident.
Unifil, the United Nations peacekeeping mission in Lebanon, urged restraint on all sides, and said in a statement that peacekeepers were now on the ground with the Lebanese army to assess the situation.
The two previous barrages, neither of which caused any casualties, were attributed to Palestinian groups in Lebanon, not Hezbollah.
But the latest incident will heighten existing fears of a much larger conflict than the war in Gaza.
Following the exchange of fire, the Israeli military warned, "we are prepared for any scenario on any front."
Unrest has been simmering on Israel’s northern border with Lebanon over the last week, as Gaza descended into all-out conflict. On Friday evening, a 21-year-old Hezbollah member was shot and killed by Israeli border guards, as he attempted to storm the border wall with a small group of demonstrators. The weekend saw huge crowds massing along the frontier, with Lebanese and Palestinians raising the Hezbollah and Iranian flags on the border wall.