Four rockets were fired on Israel Thursday, the army said, adding that two hit civilian areas causing no casualties while Prime Minister Benjamin Netanyahu vowed retaliation.
Lebanese security sources said unknown gunmen fired the rockets from the southern port of Tyre into northern Israel while an Al-Qaeda-linked group claimed responsibility for the attack.
"A barrage of four rockets was fired at the civilian communities of northern Israel," the army said in a statement.
The army said its Iron Dome missile defence system "successfully intercepted" one of the rockets between the coastal towns of Acre and Nahariya.
"Two other rockets landed in populated areas causing damage, but no injuries," the statement added, while the fourth may have fallen into the sea or elsewhere.
A security source in Lebanon said four rockets were fired at Israel from locations "south and east of Tyre," in southern Lebanon and residents in the area said they heard four blasts.
The attack was claimed by the Abdullah Azzam Brigades -- an Al-Qaeda-linked group which had claimed similar rocket fire on Israel in 2009 and 2011.
A member of the group, Sirajeddin Zureykat, made the claim in a statement posted on his Twitter account.
The Israeli army said in the statement it "holds the government of Lebanon and the Lebanese Armed Forces as the responsible bodies for this attack."
It quoted army spokesman Brigadier General Yoav Mordechai saying the rockets were "launched by the global jihad terror organisation" -- an apparent reference to Al-Qaeda.
Mordechai said that the Iron Dome battery that shot down one of the rockets had been positioned in northern Israel earlier this month "following situation assessments."
An earlier statement from the military had said that none of the rockets had hit the ground inside Israel.
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An AFP correspondent reported a hole in the ground in Gesher Haziv, a kibbutz east of Nahariya, with debris causing damage to two cars and a number of homes nearby.
Israeli army spokesman Lieutenant Colonel Peter Lerner told journalists that airspace in the north of Israel had been closed following what he described as an "unprovoked attack on Israeli citizens."
The Israeli army did not retaliate, Lerner said, and another spokesman said the army considered the attack an "isolated incident."
But Netanyahu warned of future retaliation.
"Anyone who harms us, or tries to harm us, should know -- we will strike them," he said in a televised address.
Arieh Herzog, a former director of the Israeli defence ministry's Missile Defence Organisation, warned "this kind of attack could (provoke) very serious action from our side."
He stressed, however, that missile defence capabilities were "much better" than they had been during Israel's 2006 war against Lebanese Shiite movement Hezbollah.
Lebanese President Michel Sleiman meanwhile said the rocket fire was a violation of UN resolutions and of Lebanese sovereignty and urged security forces to hunt the gunmen and bring them to justice.
The Lebanese army said the rockets used were of the Katiyusha type, adding that it was investigating the attack along with UNIFIL peacekeepers deployed in southern Lebanon.
UNIFIL commander Brigadier General Paolo Serra condemned the attack, and confirmed that an investigation was underway.
"The launching of rockets today ... shows that there are people who would like to disturb the quiet in this area... I strongly condemn this violation."
The Iron Dome batteries, which are deployed throughout Israel, can shoot down rockets with a range of up to 70 kilometres (44 miles).
Israeli police urged residents of the north to remain close to bomb shelters after Thursday's rocket fire.
It was the first such incident since November 2011, when the Abdullah Azzam Brigades fired a volley of rockets from southern Lebanon at Israel, provoking a reaction from the Israeli army.