DEIR AL-BALAH :  An Israeli strike early Thursday on a school sheltering displaced Palestinians in central Gaza killed more than 30 people, including 23 women and children, according to local health officials. The Israeli military said Hamas militants were operating from within the school.

The strike came after the military announced a new ground and air assault in several refugee camps in central Gaza, pursuing Hamas militants it says have regrouped there. It’s the latest instance of troops sweeping back into sections of the Gaza Strip they have previously invaded, underscoring the resilience of the militant group despite Israel’s nearly eight-month onslaught in the territory.

 Witnesses and hospital officials said the predawn strike hit the al-Sardi School, run by the United Nations agency for Palestinian refugees known by the acronym UNRWA. The school was filled with Palestinians who had fled Israeli offensives and bombardment in northern Gaza, they said.

Ayman Rashed, a man displaced from Gaza City who was sheltering at the school, said the missiles hit classrooms on the second and third floor where families were sheltering.

He said he helped carry out five dead, including an old man and two children, one with his head shattered open. “It was dark, with no electricity, and we struggled to get out the victims,” Rashed said. The Al-Aqsa Martyrs Hospital in the nearby town of Deir al-Balah received at least 33 dead from the strike, including 14 children and nine women, according to hospital records and an Associated Press reporter at the hospital.

Another strike on a house overnight killed six people, according to the records. Both strikes occurred in Nuseirat, one of several built-up refugee camps in Gaza dating to the 1948 war surrounding Israel’s creation, when hundreds of thousands of Palestinians fled or were driven from their homes in what became the new state.

Mohammed al-Kareem, a displaced Palestinian sheltering near the hospital, described chaotic scenes outside the facility. He said vehicles arrived one after the other, as distressed people rushed wounded people into the emergency department. Videos circulating online appeared to show several wounded people being treated on the floor of the hospital, a common scene in Gaza’s overwhelmed medical wards.

 Footage showed bodies wrapped in blankets or plastic bags being laid out in lines in the courtyard of the hospital, which was largely dark as staff try to conserve limited fuel for electricity. Al-Kareem said he saw people searching for their loved ones among bodies, and that one woman kept asking medical workers to open the wraps on the bodies to see if her son was inside.

 The Israeli military said Hamas had embedded a “compound” within the school and that Hamas and Islamic Jihad militants inside were using it as a shelter where they were planning attacks against Israeli troops, though it did not immediately offer evidence. It released a photo of the school, pointing to classrooms on the second and third floor where it claimed militants were located.

Palestinians mourn their relatives killed in an Israeli bombardment of UNRWA school at Nusseirat refugee camp, in front of the morgue of al-Aqsa Martyrs hospital in Deir al-Balah, central Gaza Strip, early Thursday, June 6, 2024.

Rights group claims Israel has hit residential buildings with white phosphorous in Lebanon .It said it took steps before the strike “to reduce the risk of harming uninvolved civilians … including conducting aerial surveillance, and additional intelligence information.”

UNRWA schools across Gaza have functioned as shelters since the start of the war, which has driven most of the territory’s population of 2.3 million Palestinians from their homes.

Israel launched its campaign in Gaza after Hamas’ Oct. 7 attack into Israel, in which militants killed some 1,200 people and took another 250 hostage. Israel’s offensive has killed at least 36,000 Palestinians, according to Gaza’s Health Ministry, which does not distinguish between fighters and civilians in its figures.

Israel blames civilian deaths on Hamas because it positions fighters, tunnels and rocket launchers in residential areas. The United States has thrown its weight behind a phased cease-fire and hostage release outlined by President Joe Biden last week. But Israel says it won’t end the war without destroying Hamas, while the militant group is demanding a lasting cease-fire and the full withdrawal of Israeli forces.

The military said Wednesday that forces were operating “both above and below ground” in eastern parts of Deir al-Balah and the Bureij refugee camp in central Gaza. It said the operation began with airstrikes on militant infrastructure, after which troops began a “targeted daylight operation” in both areas.

Doctors Without Borders said at least 70 bodies and 300 wounded people, mostly women and children, were brought to a hospital in central Gaza on Tuesday and Wednesday after a wave of Israeli strikes.

The international charity said Wednesday in a post on X that Al-Aqsa Martyrs Hospital is struggling to treat “a huge influx of patients, many of them arriving with severe burns, shrapnel wounds, fractures, and other traumatic injuries.”

Gaza’s health system has nearly collapsed through almost eight months of war. The hospital, which was treating some 700 wounded and sick people before the latest strikes, said Wednesday that one of its two electrical generators had stopped working, threatening its ability to keep operating ventilators and incubators for premature babies.

Israel has routinely launched airstrikes in all parts of Gaza since the start of the war and has carried out massive ground operations in the territory’s two largest cities, Gaza City and Khan Younis, that left much of them in ruins.

The military waged an offensive earlier this year for several weeks in Bureij and several other nearby refugee camps in central Gaza.

Troops pulled out of the Jabaliya camp in northern Gaza last Friday after weeks of fighting caused widespread destruction. First responders have recovered the bodies of 360 people, mostly women and children, killed during the battles.

Israel sent troops into Rafah in May in what it said was a limited incursion, but those forces are now operating in central parts of Gaza’s southernmost city. More than 1 million people have fled Rafah since the start of the operation, with many heading toward central Gaza