GAZA — At least 18 people, including United Nations staff, were killed in an Israeli airstrike on a UN school-turned-shelter in the Nuseirat camp in central Gaza on Wednesday, according to the Gaza Civil Defense and hospital officials. At least 44 others were injured, they said. UNRWA, the UN agency for Palestinian humanitarian relief, said on X that six of its employees were “killed today when two airstrikes hit a school and its surroundings in Nuseirat,” in what is “the highest death toll among our staff in a single incident.” The Israel Defense Forces (IDF) confirmed that the Israeli Air Force had “conducted a precise strike on terrorists” operating inside the school compound. It claimed the school “was used by Hamas terrorists to plan and execute terrorist attacks against IDF troops and the state of Israel.” The IDF said “numerous steps were taken to mitigate the risk of harming civilians,” saying this was “a further example of the Hamas terrorist organization’s systematic abuse of civilian infrastructure in violation of international law.” The strike targeted the Al Jaouni UNRWA facility, which has not operated as a functioning school since October. An estimated 12,000 displaced people, including women and children, have been sheltering in the school, said UNRWA. This is the fifth time that the school compound has been targeted since October 7, according to the UN agency and a Gaza Civil Defense spokesperson. Mahmoud Basal, a Gaza Civil Defense spokesman, said search operations were ongoing amid the rubble, with children and women among the injured. “Another school sheltering displaced people hit in Nuseirat today,” UNRWA chief Philippe Lazzarini wrote on X, adding that UN staff were working and “providing support to families who have sought refuge in the school.” “Since the beginning of this war, at least 220 UNRWA staff have been killed in Gaza,” he added. “The longer impunity prevails, the more international humanitarian law and the Geneva Conventions will become irrelevant.” Footage from the scene showed debris strewn around a compound and blood stains on the ground. A hole has punctured what appears to be a classroom and among the rubble is canned food and the dust-covered belongings of displaced Palestinians. A man carrying human remains said: “Brutality, I don’t know what to say.” Another man searches desperately for his wife and four children. “I don’t know where they are, my son, my three daughters are all missing,” Hani Haniya said from a classroom in the building. “They normally sit here, I don’t know where my wife is, she survived the last strike.” Inside a wrecked room at the school, Fadel Abu Hdayyeh said it was used to store food for displaced Palestinians. “Those who were working here were providing aid. We don’t have any resistance fighters here, none of them enter the school. Look around, it’s all food aid,” he said. “The people who were distributing the aid are the ones who died, civilians. We are all civilians here who are dying,” he added. At Al-Aqsa Martyrs Hospital, footage shows trucks and ambulances transferring injured people and bodies to the hospital. The emergency room floor is overcrowded with the injured while medical teams struggle to provide aid. Nuseirat is one of Gaza’s most densely populated camps, and its population has swollen since the war began. Since October 7, more than 41,000 people have been killed and 95,000 injured in Gaza, according to the latest figures from the Palestinian Ministry of Health. CNN cannot verify casualty numbers. Medical records in the war-torn enclave do not differentiate between civilians and militants killed. Earlier Wednesday, an Israeli bombardment killed one child and six other people in the Qizan Al-Najjar area, near Khan Younis, according to Gaza’s Civil Defense. That followed an overnight strike on a family home in the town of Khuza’a, east of Khan Younis, where at least 11 people were killed, according to the Civil Defense. In a separate attack, at least nine members of the same family were killed in an Israeli strike in Jabalya, northern Gaza, it said. Footage of the aftermath, published by Gaza’s Civil Defense, showed the dismembered limbs of children. CNN has reached out to the IDF for comment. — CNN