Footage from the aftermath of Wednesday's airstrikes showed hundreds of people inspecting the heavily damaged first floor of one of the al-Jauni school buildings and the rubble of an adjacent building that appeared to have been destroyed.
Other footage showed ambulances transporting men, women and children believed to have been injured in the airstrike to Al-Aqsa hospital in the town of Deir al-Balah.
Medical staff at Al-Awda hospital in Nusseirat camp told AFP that nine of the people killed in the airstrike were taken there, while the other six were transferred to Al-Aqsa hospital.
The Associated Press quoted hospital officials as saying that al-Awda received 10 bodies and al-Aqsa received four, including those of a woman and two children.
Civil defense spokesman Mahmoud Bassal also estimated the death toll at 14.
In a post on Telegram, the agency identified one of the dead as the daughter of rescue worker Momin Salmi, who said he had not seen Shadia in 10 months because he had stayed in northern Gaza while his wife and eight children fled south.
The Israel Defense Forces (IDF) said in a statement that the aircraft “carried out precision strikes on terrorists operating inside the Hamas command and control center” located inside the al-Jauni school.
“A number of steps have been taken to mitigate the risk of harm to civilians, including the use of precision weapons, aerial surveillance and additional intelligence gathering,” he added.
“This is yet another example of the Hamas terrorist organization systematically abusing civilian infrastructure in violation of international law.”
The Hamas-run government press office in Gaza said about 5,000 people were sheltering in the school at the time of the strike and accused Israel of carrying out a “savage massacre.”
There was no immediate comment from the United Nations Agency for Palestinian Refugees (UNRWA), which ran the al-Jauni school before the war.
The United Nations condemned “all air strikes targeting civilians and all air strikes targeting United Nations facilities.”
“Our policy is clear: UN buildings must never be targeted, and they must never be used by any group or force to launch military activities,” spokesman Stephane Dujarric told reporters.
Unrwa says about 70 percent of schools in Gaza have been damaged in the past 11 months. Many, the group says, have been severely damaged.
The agency also reported that at least 563 migrants died and 1,790 were injured while being evacuated from schools and other facilities.
Earlier on Wednesday, the IDF said a helicopter crash in the southern Gaza Strip killed two Israeli soldiers and wounded eight others.
The helicopter crashed while landing in the Rafah area while on a mission to evacuate a critically injured soldier to a hospital for treatment, the statement said.
“Initial investigations indicate that the crash was not the result of hostile action. The cause of the crash is still under investigation,” he added.
