Israeli Strike Kills Hezbollah Commander in Lebanon, Adding to Fears of Border War

On Monday the Israeli military issued the warning to leave large parts of the cities of Khan Younis and Rafah, and by Tuesday thousands of people had begun to flee. The order was followed by a night of heavy bombardment in areas of southern and central Gaza. The order came after the Israeli military said Palestinian armed groups fired a barrage of roughly 20 rockets from Gaza toward Israeli cities on Monday.

The spokesman for the U.N. secretary-general, Stéphane Dujarric, said Tuesday that his colleagues were “deeply concerned” about the impact of the order.

“People are left with the impossible choice of having to relocate — some most likely for the second or even the third time — to areas that have barely any spaces or services, or staying in areas where they know heavy fighting will take place,” he said.

The order covers more than 90 school buildings, many of which have turned into overcrowded shelters as people run out of places to stay, along with four medical facilities, Mr. Dujarric said.

Among them is the European Hospital in Khan Younis, where many were sheltering and hundreds of patients were being treated. After medical staff, patients and displaced people fled the hospital, the Israeli military said on Tuesday that it was not necessary for people to leave it.

The International Committee of the Red Cross said Wednesday that the hospital was no longer functioning because so many staff members had left.

Though many people in the evacuation zone have made the decision to flee fonce again, relocating becomes harder and harder as the war drags on.

“In terms of people’s ability to move, it’s been eight months of war, people are extremely fatigued, they’re exhausted, they’re malnourished,” Ms. Wateridge said. Health-wise, she said, “people are a lot weaker, there are more injuries, there’s been less medicine available, less fresh fruit, less water.”

More people are also fleeing on foot, she said, and so are taking fewer belongings with them.

Heba Usrof, 29, a singer who is living in Khan Younis, said she only knew of the evacuation order when she saw hundreds of people passing by outside. A few were carrying mattresses, while others had only backpacks, she said.

“They were not carrying much stuff this time,” Ms. Usrof said. “I believe they were too tired to keep carrying stuff from one place to another, and they no longer have money to pay for trucks.”

Ms. Usrof said she was living with her family of five in what was left of their two-story home, in a part of the city that is not under the evacuation order. If tanks approach their home and they have to flee again, she said, she might take only her ID, cellphone and a change of clothes.

Among the dangers facing people as they flee are unexploded bombs and other munitions, according to the United Nations. These are a particular risk for children.

A 9-year-old girl was killed and three others wounded on Saturday by unexploded ordnance south of Khan Younis, the organization reported. And six children were injured in the city last month in a similar explosion.

Abu Bakr Bashir contributed reporting from London.