Mahmoud Basal, spokesman for Gaza’s Civil Emergency Service, said the death toll could rise as many of the injured were in critical condition.
The attack on the school means that no place in the enclave is safe for families leaving their homes to seek shelter, he said in a statement.
Al-Nuseirat, one of eight historic refugee camps in the Gaza Strip, was the scene of intensified Israeli shelling on Saturday. An earlier airstrike on a house in the camp killed at least 10 people and wounded many others, according to medical workers.
In its daily tally of those killed in the nearly nine-month-old war, Gaza’s health ministry said Israeli military strikes across the enclave killed at least 29 Palestinians in the past 24 hours and wounded 100 others.
Among those killed in separate airstrikes were five local journalists, bringing the toll of journalists killed since October 7 to 158, according to the Hamas-run Gaza government’s media office.
Gaza health officials said more than 38,000 Palestinians have been killed in the Israeli offensive launched in response to a Hamas attack on Israel on October 7, in which 1,200 people were killed and more than 250 taken hostage, according to Israeli figures.
Israeli forces, which have deepened their incursions into Rafah, in the south of the enclave near the border with Egypt, killed four Palestinian policemen and wounded eight others in an airstrike on their vehicle on Saturday, health officials said.
A statement released by the Hamas-run Interior Ministry said the four included Fares Abdel-Al, the head of the police force in the Tel Al-Sultan neighborhood west of Rafah.
The Israeli military said its forces continued “intelligence operations” in Rafah, destroying several underground structures, seizing weapons and equipment and killing several Palestinian gunmen.
Israel said its operations in Rafah were aimed at eradicating the last battalions of Hamas’s armed wing.
The Israeli military announced that it had eliminated a Hamas rocket cell in Deir Al-Balah, in central Gaza, which was operating from a humanitarian zone. It said it carried out a precise strike after taking measures to ensure that civilians were not harmed.
Hamas denies Israeli accusations that it uses civilian property and facilities for military purposes.
The armed wings of Hamas and Islamic Jihad said fighters attacked Israeli forces in several areas of Gaza with anti-tank rockets and mortar shells.