A Lebanese group claims to have attacked an Israeli airbase east of Haifa with dozens of rockets following a series of Israeli strikes.
Hezbollah has said it fired dozens of rockets at Israel's Ramat David airbase east of Haifa in response to a series of Israeli strikes that killed civilians in Lebanon.
Sirens were activated across northern Israel early Sunday morning.
If confirmed, the attack would be Hezbollah's most far-reaching inside Israel since the current cross-border clashes began in October last year.
The Israeli military said 10 rockets were launched from Lebanon and most were intercepted.
On Saturday, the Israeli military said it carried out hundreds of airstrikes in southern Lebanon in an effort to thwart a Hezbollah attack.
The Israeli military also issued restrictions on large gatherings in northern Israel, including Haifa, the country's third-largest city.
There were no reports of casualties or other rocket impacts in Israel on Sunday.
Reporting from Beirut, Al Jazeera's Ali Hashem highlighted the significance of the Lebanese group's attack.
“This is the first time since the 2006 war [between Israel and Hezbollah] that Hezbollah missiles crossed” beyond 20 kilometers (12 miles), Hashem said.
“This is the first time they have hit targets within a 45km radius. [30 miles]50 kilometers [31 miles]because we are hearing reports of hits or interceptions in several areas, including over the Ramat David air base, east of Haifa.”
In its statement, Hezbollah claimed it carried out the attack with so-called Fadi 1 and Fadi 2 rockets, not the Soviet-made World War II-era Katyusha rockets it has been using for the past several months.
The latest rocket barrage comes after a week of Israeli attacks across Lebanon.
On Tuesday and Wednesday, wireless communication devices associated with Hezbollah exploded across Lebanon, injuring thousands of people and killing dozens, including civilians. Lebanon blamed Israel for the unprecedented attack.
Israel also carried out an airstrike on Beirut's southern suburbs on Friday, killing at least 38 people and wounding dozens more.
Senior Hezbollah commander Ibrahim Aqil was among those killed in the attack that leveled an entire residential building.
Hezbollah and Israel have been engaged in daily clashes since the Israeli war on Gaza broke out.
The Lebanese group says it will continue its attacks on Israeli bases in the north of the country until Israel ends its offensive in Gaza.
The violence has displaced tens of thousands of people on both sides of the border.
The two sides appear to be in a spiral of escalation that risks sparking a full-scale conflict. Hezbollah has said it does not seek all-out war but is prepared for one if it occurs.
Israeli leaders have vowed to drive Hezbollah from the border with Israel and return its citizens to northern communities, even through war if necessary.
