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.

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.

Israel’s military has been intensifying operations against Hezbollah in Lebanon in an apparent attempt to pressure the militant group into a cease-fire.