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 U.N. Security Council unanimously adopted Resolution 1701 in August 2006 as part of a cease-fire that ended Israel’s last war with Lebanon. The resolution sought to create a buffer zone in southern Lebanon to prevent fighting between Israel and Hezbollah, but has failed to keep the peace.