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.

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.

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.

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.

A powerful airstrike killed 15 people in central Beirut on Saturday and 13 others were killed in attacks northeast of the Lebanese capital, the health ministry said, as Israel pressed its offensive against the Iran-backed Hezbollah group.