World leaders will open their annual meeting at the U.N. General Assembly Tuesday under the shadow of increasing global divisions, major wars in Gaza, Ukraine and, Sudan and the threat of an even larger conflict in the wider Middle East.

Secretary-General Antonio Guterres previewed his opening "State of the World" speech to presidents, prime ministers, monarchs and ministers at Sunday's "Summit of the Future," saying "our world is heading off the rails — and we need tough decisions to get back on track."

Lebanese families displaced from villages farther south slept in shelters hastily set up in schools in Beirut and the coastal city of Sidon. Some who did not find shelter elsewhere slept in cars and parks and on the seaside corniche.

Monday’s heavy bombardment sent thousands fleeing from south Lebanon. Hotels in Beirut were quickly booked to capacity and apartments in the mountains surrounding the capital were snapped up by families seeking safe accommodations.

The U.S. is sending additional troops to the Middle East in response to a sharp spike in violence between Israel and Hezbollah forces in Lebanon that has raised the risk of a greater regional war, the Pentagon said Monday.

Pentagon press secretary Maj. Gen. Pat Ryder would provide no details on how many additional forces or what they would be tasked to do. The U.S. currently has about 40,000 troops in the region.

Israel is bombing targets across many parts of Lebanon, striking senior militants in Beirut's southern suburbs and apparently hiding bombs in pagers and walkie-talkies. Hezbollah is firing rockets and drones deep into northern Israel, setting buildings and cars alight.

But no one is calling it a war — not yet.

Thousands of people are leaving south Lebanon and heading north after Israel intensified airstrikes on Monday, leaving 100 people dead and hundreds wounded.

In the southern port city of Sidon, the main north-south highway was packed with cars heading north in the direction of the capital Beirut.

An Israeli military official said Israel is focused on aerial operations and has no immediate plans for a ground operation.

The official, speaking on condition of anonymity in keeping with regulations, said more than 300 strikes on Lebanon's south and east on Monday are aimed at curbing Hezbollah's ability to launch more strikes into Israel.

More than 200 people, including women and children, were killed Monday and more than 1000 were wounded as the Israeli military said it had targeted more than 300 Hezbollah sites in Lebanon in an unprecedented wave of air strikes.

"So far more than 300 Hezbollah sites have been targeted" since Monday morning, the military said in a statement. It earlier said more than 150 air strikes were carried out within just one hour, between 6:30 am and 7:30 am.

For almost a week, ophthalmologist Elias Jradeh has worked around the clock, trying to keep up with the flood of patients whose eyes were injured when pagers and walkie-talkies exploded en masse across Lebanon.

He has lost track of how many eye operations he has performed in multiple hospitals, surviving on two hours of sleep before starting on the next operation. He has managed to save some patients' sight, but many will never see again.

China urged Monday its citizens in Lebanon and Israel to evacuate or move to safe areas as the conflict between Israel and Lebanon’s Hezbollah is escalating.

Chinese citizens in Lebanon should take commercial flights to return to China or otherwise leave Lebanon as soon as possible for their own safety, the Consular Department of China’s Ministry of Foreign Affairs said in a statement posted on social media platform WeChat.

The Israeli defense minister says the steps taken against Hezbollah will continue until residents of Israel’s north can return to their homes, saying "we will do everything necessary to achieve it.”

Yoav Gallant was on a visit to the command and control center of the Israeli Air Force when he said Hezbollah “has started to sense some of the capabilities" of the Israeli army and that Hezbollah is now feeling "persecuted, and we are seeing the results.”