Eye-witness accounts of a shell attack in the south of Lebanon suggest thirty three rockets were launched from Israel on Sunday.
Israel is thought to be retaliating after rockets struck near the border town of Kiryat Shmona in the north of the country.
Tensions along the frontier heightened further recently when a Lebanese soldier killed an Israeli soldier across the border fence.
Israeli authorities claim five rockets were launched from Lebanon, but only one or two struck inside Israel.
It is not immediately clear who fired the rockets, but a UN peacekeeping force in south Lebanon is said to be working with the Lebanese army to determine further details of the attack.
There are no reported casualties as a result of either attack.