Israeli security and rescue forces work at the site hit by a rocket fired from Lebanon, in Kiryat Bialik. AP

Lebanon's Hezbollah launched over 100 rockets early on Sunday across a wider and deeper area of northern Israel, with some landing near the city of Haifa, as the sides appeared to be spiralling toward all-out war following months of escalating tensions.

The rocket barrage overnight set off air raid sirens across northern Israel, sending thousands of people scrambling into shelters. The Israeli military said rockets had been fired "toward civilian areas," pointing to a possible escalation after previous barrages had mainly been aimed at military targets.

Israel's Magen David Adom rescue service said it treated four people for shrapnel wounds, including a 76-year-old man who was moderately wounded in Kiryat Bialik, a community near Haifa where buildings were damaged and cars set on fire. It was not immediately clear if the damage was caused by a rocket or an Israeli interceptor.

The barrage came after an Israeli airstrike in Beirut on Friday killed at least 45 people, including one of Hezbollah's top leaders as well as women and children. Hezbollah was already reeling from a sophisticated attack that caused thousands of personal devices to explode just days earlier.

The Israeli military said it carried out a wave of strikes across southern Lebanon over the past 24 hours, hitting some 400 militant sites, including rocket launchers. Lt. Col. Nadav Shoshani, an Israeli military spokesman, said those strikes had thwarted an even larger attack.

"Hundreds of thousands of civilians have come under fire across a lot of northern Israel. They spent the night and now the morning in bomb shelters," he said. "Today we saw fire that was deeper into Israel than before.”

In a separate development, Israeli forces raided the West Bank bureau of Al-Jazeera, which it had banned earlier this year, accusing it of serving as a mouthpiece for militant groups, allegations denied by the pan-Arab broadcaster.

Associated Press