Thousands of people fled their homes in southern Lebanon after Israel killed hundreds in intensified airstrikes through Monday and Tuesday.

The mass movement of people -- encouraged by the Israel Defense Forces before and during its expanding bombing campaign -- prompted gridlock on highways running north toward the capital Beirut.

A journey that usually takes 90 minutes took up to 13 hours.

Authorities are working to turn schools and other educational institutions into makeshift shelters to house displaced people.

-ABC News’ Joe Simonetti

The Israel Defense Forces said Tuesday its warplanes struck “dozens of Hezbollah targets in southern Lebanon,” with artillery and tanks also conducting fire missions in the area.

Hezbollah, meanwhile, fired at least 125 rockets overnight into Tuesday morning. Sirens were sounding through the early morning in northern Israel.

At least nine people suffered minor injuries as a result of rockets fired into the Western Galilee region of northern Israel on Tuesday morning, according to Israel’s Magen David Adom emergency service.

At least 492 people were killed in Lebanon by Israeli strikes on Monday, according to Lebanese authorities. At least 1,645 people were reported injured.

The IDF said it struck at least 1,600 targets in Lebanon over the past 24 hours.

-ABC News’ Joe Simonetti

A senior official in President Joe Biden's administration told ABC News the U.S. cannot rule out the possibility of an Israeli invasion into Lebanon following the escalation of its airstrike campaign on Monday.

"I think it is important for everyone to take Israeli preparations seriously," the senior administration official said.

The U.S. is putting its hope in engagements on the sideline of the United Nations General Assembly this week, said the senior administration official, who expressed hope that the informal meetings could lead to "illusive solutions" or "at least make some progress" toward resolving the crisis in the Middle East.

The official said Secretary of State Antony Blinken would discuss "the increasing challenges" across the so-called "Blue Line" dividing Israel and Lebanon at a meeting with his G7 counterparts.

At that engagement and through the week, the a key U.S. focus will be "finding an off ramp," they said.

"We've got some concrete ideas with allies and partners we are going to be discussing," the official added.

-ABC News' Shannon Kingston

A U.S. official tells ABC News that the "small number of additional U.S. military personnel being sent to the Middle East," announced this morning by the Pentagon is a small special operations team that will work in planning for a non-combatant evacuation operation should itbe needed.

-ABC News' Luis Martinez