"Three martyrs and more than 20 wounded people were retrieved after an Israeli warplane fired two missiles at a prayer room and a classroom at the Amr Ibn al-Aas School, where refugees were sheltering in the Sheikh Radwan neighbourhood in northern Gaza City," Mahmud Bassal, spokesman for the civil defence agency, told AFP.

The Israeli military said it conducted a "precise strike" at the school.

The strike targeted "terrorists who were operating inside a Hamas command and control centre... embedded inside a compound that previously served as Amr Ibn al-Aas school," the military said in a statement.

A large crowd gathered outside the building in the aftermath of the strike, picking their way over rubble as emergency workers tried to help the wounded, AFPTV footage showed.

Displaced Gazan Abd Arooq said the school had served as a shelter for more than 2,000 people.

"We don't know where to go. We are in the street," he said.

"There is no sanctity for mosques, schools or even the houses we live in."

In recent months, Israeli forces have struck several schools that were housing displaced Palestinians, many of them in Gaza City, saying the strikes targeted Hamas militants.

Tens of thousands of displaced people have sought refuge in schools since the war in Gaza, which entered its 12th month on Saturday, broke out following Hamas's attack on southern Israel on October 7.

That attack resulted in the deaths of 1,205 people, mostly civilians and some hostages killed in captivity, according to official Israeli figures.

Israel's retaliatory military offensive has so far killed at least 40,939 people, according to the health ministry in the Hamas-run Gaza Strip.

According to the United Nations human rights office, most of the dead are women and children.

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