The Israeli military says that the rockets were landed in the Mediterranean Sea and no casualties reported as it was unclear who was responsible for the attack.
Three rockets have been launched from Lebanon toward northern Israel but landed in the Mediterranean Sea, causing no damage or casualties, according to the Israeli military.
There was no immediate comment from Beirut about the rare incident.
Israel and Palestinian groups in Gaza have been trading fire this week in their worst hostilities for years.
The latest incident did not appear to signal the opening of a new front.
"A short while ago, three rockets were fired from Lebanon into the Mediterranean Sea off the coast of the Galilee," Israel's army said in a statement.
"According to protocol no sirens were sounded," - an allusion to Israeli air defences that ignore rockets set to hit unpopulated areas.
First such incident in years
Two sources close to Israel's arch-enemy Hezbollah said the Lebanese Shia group had no link to the incident.
Israel fought a 2006 war against Hezbollah fighters, who have sway in southern Lebanon and advanced rockets.
A UN-brokered ceasefire has largely kept the border area quiet since then, but the sides have had several small clashes in the years since, most recently last summer.
In November, the military also said it downed a Hezbollah drone that entered Israeli airspace.
Small Palestinian factions in Lebanon have fired sporadically on Israel in the past.
A witness in the northern Israeli port city of Haifa said she heard three explosions shortly before the rocket salvo was reported.