BEIRUT, Lebanon >> 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.

Lebanon’s Health Ministry said 66 people were wounded in the strikes, which were the fourth in central Beirut in less than a week.

The escalation comes after U.S. envoy Amos Hochstein traveled to the region in pursuit of a deal to end months of fighting between Israel and Hezbollah that has erupted into full-on war.

Israeli attacks have killed more than 3,500 people in Lebanon, according to Lebanon’s Health Ministry. The fighting has displaced about 1.2 million people, or a quarter of Lebanon’s population. On the Israeli side, about 90 soldiers and nearly 50 civilians have been killed by bombardment in northern Israel and the fighting. An eight-story building is turned to rubble

The 4 a.m. strikes destroyed an eight-story building in central Beirut. Hezbollah legislator Amin Shiri said no Hezbollah officials were inside. The attack stripped the facades from some nearby buildings and crumpled cars.

“The area is residential, with closely packed buildings and narrow streets, making the situation challenging,” said Walid Al-Hashash, a first responder with the Lebanese Civil Defense. Israel’s military did not comment on the casualties.

Also Saturday, a drone strike killed two people and injured three in the southern Lebanese port city of Tyre, according to the Lebanese state-run National News Agency.

Cease-fire talks

Two Western diplomatic officials on Saturday described disputed points between Israel and Lebanon in cease-fire negotiations. They spoke on the condition of anonymity because they were not authorized to discuss the talks.

The current proposal calls for a two-month cease-fire during which Israeli forces would withdraw from Lebanon and Hezbollah would end its armed presence along the southern border south of the Litani River.

Thousands more Lebanese army troops would patrol the border area with U.N. peacekeepers, and an international committee would monitor the deal’s implementation.

The officials said Israel wanted more guarantees that Hezbollah’s weapons are removed from the border area.

Israeli officials have said they would not agree to a deal that did not explicitly grant them freedom to strike in Lebanon if they believe Hezbollah is violating it.

Lebanese officials have said the inclusion of such a term would violate their country’s sovereignty.