Seven days after Israel’s military began a raid on the Gaza Strip’s largest hospital, Al-Shifa, a picture of the sustained assault on the complex and its surrounding neighborhood emerges in fragments.

Residents nearby described a relentless daily soundtrack of gunshots, airstrikes and explosions. A surgeon spoke of doctors and patients corralled in the emergency ward while Israeli forces took control of the complex outside. A Palestinian teenager who spent four days sheltering in the hospital described the bodies she saw piled up outside the entrance.

“They had put the bodies on the side and thrown blankets over them,” said Alaa Abu Al-Kaaf, 18, who said she and her family were at Al-Shifa for days before leaving on Thursday. It was not immediately clear when or how the bodies were taken there.

Interviews with other witnesses in the hospital, residents in or near the facility and the Gazan authorities in recent days, as well as with others who have left the complex over the past week, described a situation of fear and deprivation, interrogations and detentions of Palestinian men by Israeli forces, and a persistent lack of food and water.

The assault on Al-Shifa, one of Israel’s longest hospital raids of the war in Gaza, began last Monday with tanks, bulldozers and airstrikes. The military said it was aimed at senior officials of Hamas, the armed group that led an attack into southern Israel on Oct. 7. Israel began a war on Gaza in response to that assault, with intense aerial bombardments and a ground offensive.

In recent weeks, mediators have redoubled efforts to reach a cease-fire deal between Israel and Hamas, hosting indirect talks between the two parties in Doha. Qatar, a key mediator, has voiced cautious optimism but says the talks have yet to see a breakthrough.

Israeli leaders have said that regardless of whether a cease-fire deal is reached, they intend to start a ground operation in the southern city of Rafah to root out Hamas’s remaining forces there. The prospect has prompted international concern for the fate of the over one million Palestinians who have crowded into the area seeking shelter.

Defense Secretary Lloyd J. Austin III recently “raised the need to consider alternatives to a major ground operation in Rafah” during a phone call with his Israeli counterpart, Yoav Gallant. Mr. Gallant is traveling to Washington on Sunday to meet with Mr. Austin and other top U.S. officials, his office said.

The raid on Al-Shifa has also focused international attention on the dire situation faced by hospitals and the patients sheltering there, according to local authorities. Many of the 30,000 Palestinians who the Gaza Health Ministry said had been sheltering at Al-Shifa were displaced once again by the raid.

The Gazan authorities said that at least 13 patients had died as a result of the raid because they were deprived of medicine and treatment, or when their ventilators stopped working after the Israelis cut the electricity. Those claims could not be verified.

The Gaza Health Ministry said on Saturday that patients still in Al-Shifa were in critical condition, with maggots beginning to infect wounds.

The director general of the World Health Organization, Dr. Tedros Adhanom Ghebreyesus, posted a report on social media on Friday from a doctor in Al-Shifa, as relayed by a colleague from the United Nations.

Two patients on life support died because of a lack of electricity, and there were no medicines or basic medical supplies, he wrote. Many patients in critical condition were lying on the floor.

In one building, 50 medical workers and more than 140 patients have been kept since the second day of the raid, with extremely limited food, water and one nonfunctional toilet, Dr. Tedros wrote.

“Health workers are worried about their own and their patients’ safety,” Dr. Tedros wrote. “These conditions are utterly inhumane. We call for an immediate end to the siege and appeal for safe access to ensure patients get the care they need.”

Dr. Tayseer al-Tanna, 54, a vascular surgeon, said he finally fled Al-Shifa on Thursday after days of hearing gunfire outside the ward where he was positioned. Dr. Al-Tanna said Israeli forces had gathered doctors and patients in the complex’s emergency room while they swept the grounds outside.

“The Israeli military didn’t treat us violently,” Dr. Al-Tanna said. “But we had almost no food and water” during the incursion, he added.

He declined to comment on whether Palestinian fighters had fortified themselves in the medical complex.

The media office for the territory’s government, which is run by Hamas, said in a statement on Saturday that the Israeli military was threatening the medical staff and people sheltering inside to either leave the hospital — and risk being interrogated, tortured or executed — or the military would bomb and destroy the buildings over their heads. The media office said it was in touch with people inside the complex.

The Israeli military did not address specific questions about whether it had threatened people inside the medical complex. But on Saturday it said it was operating in the area of the hospital “while avoiding harm to civilians, patients, medical teams and medical equipment.”

The military said it had killed more than 170 fighters in the area of the hospital and detained and questioned more than 800 people.

The New York Times could not verify either the Hamas or Israeli military accounts.

Israel, which has long accused Hamas of using Al-Shifa and other hospitals in Gaza for military purposes, has struggled to prove its early claim that the group maintained a command and control center beneath the facility. Hamas and hospital administrators have preciously denied the accusation.

Evidence examined by The New York Times suggests Hamas has used the hospital for cover, stored weapons inside it and maintained a hardened tunnel beneath the complex that was supplied with water, power and air-conditioning.

American officials have said their intelligence includes evidence that Hamas used Al-Shifa to hold at least a few hostages since Oct 7.

In a statement on Sunday, the Palestinian Red Crescent said that Israeli forces were “besieging” two more hospitals in the southern city of Khan Younis, Al-Amal and Nasser.

The Israeli military was targeting Al-Amal with smoke bombs, and military vehicles were barricading the entrances of the compound, the Red Crescent said.

The Palestinian Authority’s foreign ministry said an Israeli assault on Nasser Hospital had been “violent and bloody” and accused the military of trying to incapacitate all the hospitals in Gaza.

The Israeli military said in a statement on Sunday that it had started an operation in the Al-Amal neighborhood of Khan Younis overnight. When asked whether Israeli troops were currently encircling Al-Amal and Nasser Hospitals, the military said it was “operating in the entire Al Amal area” and “not currently operating in the hospitals.”

In statements regarding the Al-Shifa raid, Hamas confirmed that its fighters were engaged in clashes with Israeli forces near the hospital. In one statement on Saturday, Hamas said members of its Qassam Brigades had fired mortar shells at Israeli forces near Al-Shifa.

Ms. Al-Kaaf and other Palestinians who have left the complex over the past week also described scenes in which groups of men were detained, stripped and questioned by Israeli soldiers. Women and children were separated from the men, Ms. Al-Kaaf said, and others — including members of the hospital’s medical staff, doctors and nurses — were kept in a large pit, sitting on the ground. Some were blindfolded and handcuffed.

The Israeli military said “individuals suspected of involvement in terrorist activity” were being detained and questioned in accordance with international law and released if “found not to be taking part in terrorist activities.” It added, “It is often necessary for terror suspects to hand over their clothes such that their clothes can be searched and to ensure that they are not concealing explosive vests or other weaponry.”

In Al-Rimal, the neighborhood that surrounds Al-Shifa, the siege on the hospital has trapped residents in their homes. Several said snipers had been shooting into the surrounding streets; residents were fearful they could be dragged from their homes by Israeli forces, stripped and interrogated, as they said dozens had been over the past week.

“The situation is really bad,” said Mohammed Haddad, 25, who lives about a half-mile from the hospital. “For more than five days, we haven’t been able to go out and move around. We haven’t been able to get water, get food. And it’s Ramadan,” he said, referring to the Muslim holy month of fasting.

Airstrikes and random cannon fire have hit multiple homes in the immediate neighborhood, demolishing them, Mr. Haddad said.

“There are snipers, shelling, surveillance drones and armed drones,” he added, the buzzing of a drone audible as he spoke on the phone.

Israeli forces appeared to be destroying the entire area, he said, “not just the hospital.”

Rawan Sheikh Ahmad and Aaron Boxerman contributed reporting.