Local journalists and residents said the latest strike took place in the early hours of Thursday at Al Sardi School, southeast of the densely populated, decades-old camp. , provides services.
Videos shared on social media showed several classrooms in one of the school buildings destroyed and bodies wrapped in white shrouds and blankets.
The dead and wounded were rushed to Al-Aqsa Martyrs' Hospital in the nearby town of Deir al-Balah, which has been overwhelmed since Israeli forces launched a new ground operation against Hamas in central Gaza this week.
The BBC is trying to confirm details of the strike in the Nuceirat camp. Reports on the exact death toll varied.
Gaza's Hamas-run health ministry said 40 people, including 14 children and nine women, were killed and 74 wounded.
Unrwa chief Philippe Lazzarini said at least 35 people were dead and many more were injured. Juliette Touma, the agency's director of communications, told the BBC the figures came from Unrwa's “colleagues in the field”.
Eyewitnesses described harrowing scenes following the strike.
“I was sleeping when the incident happened.” Uday Abu Elias, a resident at the school, told BBC Arabic.
“Suddenly we heard a loud explosion and broken glass and debris from the building fell on us. Smoke filled the air and we couldn't see anything. We didn't expect to make it out alive. We heard someone calling for survivors. “I struggled as I stumbled upon the bodies of martyrs beneath the rubble.”
Unrwa said 6,000 people were sheltering in the school complex at the time. Many schools and other UN facilities have been used as shelter by the 1.7 million people who fled their homes during the nearly eight-month war.
U.N. Secretary-General Antonio Guterres condemned the airstrikes through his spokesman, saying U.N. buildings were “inviolable” and must be protected by “all parties” during the conflict.
