A rocket fired from Lebanon has landed in northern Israel, wounding three people and prompting Israel to respond with an artillery barrage, the Israeli army said.
A Lebanese security source said, however, that two rockets had been fired at Israel from near the city of Tyre on Saturday, and that Israel had responded by firing at least six shells into southern Lebanon.
The Lebanese army said it found two wooden rocket launchers in the Qleileh-Mansouri area, south of Tyre.
There was no immediate claim of responsibility by any group in Lebanon, while the Israeli army confirmed it had responded to the rocket fire with an artillery barrage.
Al Jazeera's Rula Amin, monitoring developments from Beirut, said it was the third time rockets had been fired from Lebanon into Israel since the military assault on the Gaza Strip.
She said officials of Hezbollah, the Lebanese group, had told her that they did not need to issue a denial "because when they do something they usually claim responsibility".
Hezbollah and Israel fought a war in the summer of 2006.
Fouad Siniora, the Lebanese prime minister, in a statement described the Israeli shelling as an inexcusable breach of Lebanon's sovereignty.
He reaffirmed Lebanon's commitment to the UN Security Council resolution 1701, saying the attack was a threat to the country's security and stability and a breach of the resolution.