Dozens of people have been killed by Israeli strikes in Lebanon, including 20 who died after a strike flattened a multi-story residential building in central Beirut overnight, according to Lebanese officials.

Lebanon's Hezbollah movement fired heavy rocket barrages at Israel on Sunday, and the Israeli military said houses had been destroyed or set alight near Tel Aviv, after a powerful Israeli airstrike killed at least 29 people in Beirut the day before.

Saturday’s attack completely demolished a multi-story building in a densely-populated neighborhood. Israel did not say who the strike’s target was.