A Lebanese official said the rocket attack on northern Israel was a violation of UN Security Council resolution 1701, Saudi Arabian al-Arabiya TV reported Thursday.
UN resolution 1701 ended the 34-day war between Hezbollah and Israel in 2006, and prohibited any attacks from Lebanon on Israel.
Meanwhile, the Lebanese army released a statement saying "Two or three rockets were fired by an unknown side against Israel, at a time Israeli artillery shells were fired north of Nakoura, on the Lebanese borders."
The Lebanese army added that the military and UN peacekeepers are adopting measures to bring the situation back to normal.
As no side claimed responsibility for the rocket attack, Hamas movement in Lebanon denied any responsibility, saying it was not behind the rocket attack on northern Israel.
Hezbollah sources also denied any knowledge about the attack.
Anwar Rajja, spokesman of the Palestinian Front for the Liberation of Palestine (PFLP), did not confirm or deny his group' s involvement, saying "Israel does not have the right to ask who fired the rockets."
Katyusha rockets were launched Thursday morning from southern Lebanon, slightly wounding four Israelis. Israel responded with shelling the area where the rockets were launched from, reported Xinhua .