- Israel's military said it had struck the location on Saturday, describing its target as a Hamas command centre embedded in the school.
- According to Gaza's civil defence agency, the strike in the Daraj district killed at least 90 people and injured dozens more.
Gaza's Hamas-controlled civil defence agency says dozens of people have been killed in an Israeli air strike on a shelter in a school in Gaza City.
Israel's military said it had struck the location on Saturday, describing its target as a Hamas command centre embedded in the school.
According to Gaza's civil defence agency, the strike in the Daraj district killed at least 90 people and injured dozens more.
The BBC has been unable to independently verify the figures.
"The death toll is now between 90 to 100 and there are dozens more wounded," agency spokesman Mahmud Bassal told AFP news agency.
"Three Israeli rockets hit the school that was housing displaced Palestinians."
Earlier in a Telegram post he described the scene as a "horrific massacre" saying crews were trying to control a fire in order to rescue the wounded and retrieve bodies.
The strike hit when people sheltering at the school were performing dawn prayers, leading to many casualties, according to a statement from the Hamas media office quoted by Reuters.
Medics had not yet been able to reach all the bodies, the statement said.
Israel's military said it had "precisely struck Hamas terrorists operating within a Hamas command and control centre embedded in the Al-Taba'een school".
Earlier this week, the Israel Defense Forces (IDF) said they had targeted Hamas "command and control centres" within two schools in Gaza City.
Hamas-led gunmen killed about 1,200 people in an attack on Israel on 7 October, taking 251 others back to Gaza as hostages.
That attack triggered a massive Israeli military offensive on Gaza and the ongoing war.
More than 39,600 Palestinians have been killed in the Israeli campaign, according to Gaza's Hamas-run health ministry.