Israeli airstrikes Saturday in central Beirut killed at least 20 people, officials said, as the once-rare attacks on the heart of Lebanon's capital continued without warning while diplomats scrambled to broker a cease-fire.

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.

At least 20 people were killed in a powerful Israeli strike that flattened a multi-storey building in densely populated central Beirut, Lebanese officials said on Saturday, as more deaths were reported from Israeli attacks in eastern Lebanon.