Exhausted Gazans defy evacuation orders as Israel presses new offensive

But many Palestinians are staying put, because they are trapped by fighting around them, exhausted by a year of repeated evacuations or fearful that nowhere in the Gaza Strip is safe.

The evacuation demands, affecting parts of Gaza City, Jabalia camp and the northernmost swath of the strip, are the most sweeping since Israel’s operation in May to take the Rafah area in southern Gaza.

The orders come as the Israeli military says it is aiming to stop Hamas from regrouping in the north of the enclave, particularly in Gaza City and the densely built Jabalia camp.

Samah Al-Haddad, a 30-year-old English teacher from Gaza City, said she is determined to stay in her family home despite the intensity of airstrikes and ground fire. She said she has heard of people being killed while trying to flee south. Some of her relatives made it but haven’t found shelter or safety, she said.

“I could never consider evacuating to the south," she said. “They’re living in tents, and the situation there isn’t any better" than in the north.

While Israel expands its campaign against Hezbollah in Lebanon, its war on Hamas in Gaza rumbles on with little indication that Israel is close to its declared goal of destroying the militant Palestinian group.

With political plans for Gaza still on the drawing board, the continued lack of clarity over who should govern Gaza after Hamas has left a vacuum that the U.S.-designated terrorist group has sought to exploit, seeking to reassert its authority and recruit new members in areas that Israeli forces have left.

Israel’s military “is operating with great force against the terrorist organizations and will continue to do so for a long time," Israel’s Arabic-language spokesman said in a social-media post over the weekend, urging civilians in the north to head south.

The latest Israeli offensive in Gaza is raising alarm bells among humanitarian organizations, who say it has become significantly harder to feed and treat the population remaining in the north.

About 50,000 people have moved from the areas under Israeli evacuation orders to other parts of Gaza City, according to the United Nations. Only about 100 people have headed south so far, crossing the Israeli military road that divides the strip south of Gaza City, said Sam Rose, a senior official at the U.N. Relief and Works Agency.

“There have been evacuation orders for places that people just evacuated to," said Rose. The recent intensification of the war has made humanitarian-aid operations considerably more difficult, he said.

For the past two weeks Israel kept closed the crossings used by aid trucks to reach northern Gaza, humanitarian groups say. On Monday, a World Food Program delivery of 30 trucks containing food was permitted to enter northern Gaza.

Lt. Col. Elad Goren, the Israeli officer in charge of civil affairs in Gaza, said the military had closed the crossings to facilitate troop movement in and out of the enclave during the new operation. He said Israel is allowing more aid deliveries to use the crossings this week.

The U.S. has been pressing Israel to reopen the crossings and increase the flow of aid to northern Gaza, according to people familiar with the matter.

Mahmoud Basal, spokesman for Gaza’s first-responder agency, said that Israeli forces have besieged the Jabalia camp for over a week, and that a large number of dead are in the streets while many wounded remain trapped under rubble, with first responders unable to reach them amid the fighting.

Doctors at hospitals in the north say they have received calls from the Israeli military ordering them to leave and that fuel deliveries have been blocked from entering medical centers.

“We believe that Israel wants to empty hospitals in the north to force everyone here to leave to the south," said Hussam Abu Safiya, director of the north’s Kamal Adwan Hospital in the north. “We are not leaving, as long as people here need us."

Israeli officials deny that the military is seeking to forcefully evacuate the whole of northern Gaza or shut down its hospitals. The military says its latest operation against Hamas in the area, including the accompanying evacuation effort, is in keeping with other raids this year.

Israel’s military said Tuesday that it helped oversee the transfer of some patients and staff from the Kamal Adwan Hospital to other hospitals in the strip. The army also said that fuel and blood supplies donated by Unicef were delivered to hospitals in northern Gaza so they could keep working while the military operation continued.

Israel’s invasion of Gaza, which followed Hamas’s attack on southern Israel on Oct. 7 last year, began in the north of the strip. Israeli forces conducted major offensives in Jabalia last winter and again in May. Their third effort to clear the area highlights Hamas’s ability to recuperate despite being outgunned and taking heavy casualties.

Israel’s military says it has killed more than 15,000 Hamas militants in the past year of fighting. Intelligence officials from Arab countries say Israel’s estimate is over optimistic and Hamas’s losses, while severe, are closer to 10,000.

Hamas, which had an armed force of around 25,000 to 30,000 fighters before the war, has for months been recruiting new members, although Israeli military analysts say they are less effective than the thousands of experienced fighters and commanders Hamas has lost.

Over 42,000 Palestinians have been killed in Israel’s invasion of Gaza, according to Palestinian health authorities, whose numbers don’t distinguish between civilians and combatants.

Reda Kaik, a 27-year-old mother in Gaza City, said the Israeli military operations this month have been the most intense since the heavy bombardment of northern Gaza when the war began. “We constantly hear the sounds of bombing and drones," she said. “It is terrifying."

The U.N. says southern Gaza is already inundated with refugees from around the strip and that aid groups can’t cope with another large influx of displaced civilians.

Kaik said she is hearing the same from family members sheltering in the south, and that it isn’t safe from Israeli airstrikes or ground fighting either.

“The people in the south advise us not to come," Kaik said. Her immediate family has decided to stay in Gaza City even as the fighting inches closer. “I just hope that if we die, my son and I die together."

Summer Said and Alexander Ward contributed to this article.

Write to Omar Abdel-Baqui at omar.abdel-baqui@wsj.com and Dov Lieber at dov.lieber@wsj.com