The strikes, which destroyed an eight-story building and left a crater in the ground, were the fourth in Beirut in less than a week.

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.

The envoy, Amos Hochstein, was in Israel and planned to meet with Prime Minister Benjamin Netanyahu, seeking a truce in the country’s war with the militant group Hezbollah.

The escalation comes after a U.S. envoy traveled to the region to pursue a deal to end months of fighting between Israel and Hezbollah.

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

The strikes at 4 a.m. destroyed an eight-story building in central Beirut and left a crater in the ground. Also on Saturday, a drone strike killed two people and injured three in the southern port city of Tyre, according to the state-run National News Agency.

The ambassador arrived in Beirut on Tuesday, seeking a ceasefire agreement after the Lebanese government and Hezbollah agreed to a U.S. ceasefire proposal

Prime Minister Benjamin Netanyahu was blunt about that strategy, telling the Knesset plenum on Monday, that Israel was negotiating under fire.

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.

Israeli officials have demanded freedom to strike Hezbollah in Lebanon as part of any emerging cease-fire deal between the sides, raising a potential complication as a top U.S. envoy was in the region

Hezbollah chief Naim Qassem said in a televised speech aired on Wednesday that his group had reviewed and given feedback on a U.S.-drafted ceasefire proposal to end fighting with Israel, and that a halt to hostilities was now in Israel's hands.