Israel’s military deployed around 100 fighter jets to launch a massive bombing campaign in southern Lebanon on Sunday, endangering tens of thousands of civilians and heightening the chances of an all-out regional war.

The Israel Defense Forces (IDF) characterized the wave of airstrikes as an effort to preemptively “remove the threat” posed by a purportedly imminent Hezbollah attack, but observers argued the Israeli bombing marked a serious escalation that could further undermine hopes of a cease-fire deal in Gaza.

“Looks like Israel is now escalating in Lebanon in a major way in the hopes of kicking off a major war in the north that has thus far been kept to more limited exchanges,” wrote political analyst Yousef Munayyer. “Just as negotiations for a cease-fire were reportedly advancing.”