Palestinians who fled the ongoing Israeli raid on the main hospital in Gaza described mass arrests and forced marches in front of bodies in interviews on Sunday, while the United Nations said Israel is now preventing its main agency that assists Palestinians from sending food aid to the devastated northern Gaza Strip.

The Israeli military said it killed more than 170 militants and about 480 suspects in the raid on Al-Shifa Hospital that began on Monday, describing it as a heavy blow to Hamas and other armed groups it says have regrouped there as the war nears six months.

The fighting highlights the ability of Palestinian armed groups to withstand in a heavily destroyed part of Gaza, where Israeli forces had to retreat after a similar raid in the early weeks of the war.

Kareem Ayman Htatat, who lived in a five-story building about 100 meters from the hospital, said he stayed in the kitchen for several days while explosions sometimes shook the building.

Early Saturday, Israeli forces stormed the building and forced dozens of residents to leave. He said men were forced to strip down to their underwear and four of them were arrested. The rest were blindfolded and ordered to follow a tank south as explosions roared around them.

He told The Associated Press, “From time to time, the tank fires a shell to terrorize us.”

Israeli planes carried out several airstrikes near Al-Shifa Hospital on Sunday, which had largely ceased operations after a November raid. After claiming Hamas kept a sophisticated command center there, Israeli forces revealed months ago a tunnel leading to a few underground rooms.

Almost no aid has been delivered in recent weeks to northern Gaza and Gaza City, where Al-Shifa is located. The isolated area suffered widespread destruction in the early days of the Israeli attack that began after the Hamas attack on October 7, which triggered the war.

UNRWA Director-General Philippe Lazzarini said on social media that Israel informed the United Nations Relief and Works Agency for Palestine Refugees (UNRWA) as of Sunday that it will no longer approve the agency’s food convoys to northern Gaza.

He said, “This is disgraceful and constitutes a deliberate obstruction of life-saving aid amid a man-made famine.” Israel repeatedly accuses the agency, the largest humanitarian provider in Gaza, of having ties to Hamas. The Israeli government did not immediately respond.

Experts say famine is imminent in northern Gaza, where more than 210,000 people suffer catastrophic hunger.

After standing near an estimated 7,000 aid trucks waiting to enter Gaza and describing the famine as a “moral outrage,” UN Secretary-General Antonio Guterres called for an immediate humanitarian ceasefire, the release of hostages held in Gaza, and removing Israel’s “obstacles and choke points” to allow a flow of aid deliveries.

Guterres said in Egypt, “Looking at Gaza, it seems the four horsemen of war, famine, invasion, and death are running through it,” adding that nothing justifies collective punishment of Palestinians.

The Gaza Health Ministry said five wounded Palestinians trapped in Al-Shifa Hospital died without food, water, or medical services. WHO Director-General Tedros Adhanom Ghebreyesus described the conditions as “completely inhumane.”

Jamil Al-Ayyubi, who was among thousands who sought refuge at Al-Shifa Hospital when the current raid began, said tanks and armored bulldozers stormed the hospital courtyard and crushed ambulances and civilian vehicles. He saw tanks running over at least four bodies of people killed in the raid.

The Israeli military said Saturday it evacuated patients and medical staff from the emergency department at Al-Shifa Hospital because militants "fortified themselves" there and established an alternative site for severely wounded patients.

Obeid Radwan, who lives about 200 meters from the hospital, said Israeli forces stormed all the buildings in the area, arrested several people, and forced the rest to walk south. He saw bodies in the streets and several homes razed to the ground.

He added, “They left nothing intact.”

The Palestinian Red Crescent Society said early Sunday the Israeli army stormed Al-Amal and Al-Nasser hospitals in Khan Younis city in the south amid “very intense shelling.” The Israeli army announced operations in Khan Younis targeting Hamas infrastructure, saying it “eliminated terrorists at close range using tank fire.” The army said forces are currently not operating inside hospitals.

The war has killed at least 32,226 Palestinians, according to Gaza's Health Ministry. The organization does not differentiate between civilians and fighters in the death toll, but says women and children make up about two-thirds of the dead.

Israel says it has killed more than 13,000 militants without providing evidence. It blames civilian casualties on Hamas and accuses it of using schools, hospitals, and residential areas.

More than 80 percent of Gaza’s 2.3 million population have fled their homes, with most seeking refuge in Rafah city at the southernmost part of the Strip, which Israel describes as the next target for its ground offensive. Prime Minister Benjamin Netanyahu rejects calls from the United States and others to avoid a large ground operation there, calling it necessary to defeat Hamas.

Israeli Defense Minister Yoav Galant said he was traveling to the United States on Sunday at Washington’s invitation, aiming to maintain “our ability to acquire aerial systems and ammunition” for the war and preserve important relations with Israel’s biggest ally.

The Hamas-led attack on October 7 through southern Israel killed about 1,200 people, mostly civilians, and took dozens hostage. Hamas still holds an estimated 100 hostages and the remains of 30 others. Most of the remainder were released in exchange for some Palestinian prisoners in November.

The United States, Qatar, and Egypt are trying to mediate a ceasefire and prisoner release.

Jews across the border from Gaza on Sunday celebrated their most joyous holiday, Purim, a biblical story about how a plot to exterminate Jews in Persia was foiled as a testament to Jewish survival.

The war has triggered instability across the region, including a low-level conflict between Israel and the Lebanese Hezbollah group. An Israeli airstrike hit a car in the Lebanese town of Al-Sweiri on Sunday, killing a Syrian construction worker, according to Lebanese official media.