The vast majority of the Gaza Strip's 2.4 million people have been displaced at least once by the war, triggered by Hamas's October 7 attack on Israel, with many seeking safety in school buildings.

Israeli forces have struck several such schools in recent months, saying Palestinian militants were operating there and hiding among displaced civilians, charges denied by Hamas.

The Al-Jawni school in central Gaza's Nuseirat, already hit several times during the war, was struck again on Wednesday, civil defence agency spokesman Mahmud Bassal told AFP.

"The number of martyrs has risen to 14," he said, updating an earlier toll of 10 killed in the "Israeli bombing of Al-Jawni school" which also wounded numerous people.

AFP was unable to independently verify the toll, which the spokesman said included several women and children.

A medical source at Nuseirat's Al-Awda health centre in central Gaza told AFP that 15 people killed in the strike had been brought to hospitals in the area.

Nine were brought to Al-Awda, and six to Al-Aqsa Martyrs's Hospital, in the central Gaza city of Deir el-Balah.

AFP journalists witnessed several unconscious men and women brought to Al-Aqsa hospital on stretchers, or in the arms of medics in the case of children.

"Most of the people took refuge in schools and the schools were bombed and the martyrs were mostly children and women," Basil Amarneh, a local, said at the hospital.

"Where will people go?"

The Israeli military said its air force had "conducted a precise strike on terrorists who were operating inside a Hamas command-and-control centre" on the school grounds, without elaborating on its outcome or the identities of those targeted.

The Hamas government media office said about 5,000 displaced people were sheltering at the school, which used to be run by the United Nations agency for Palestinian refugees UNRWA, when it was hit on Wednesday.

Al-Jawni has been hit at least five times in more than 11 months of war, Bassal said.

In July, at least 16 people were killed in an Israeli air strike on the school that the military said had targeted "terrorists".

Israel's military offensive since the October 7 attack has killed at least 41,084 people in Gaza, according to the territory's health ministry. The UN rights office says most of the dead are women and children.

The Hamas attack on southern Israel that triggered the war resulted in the deaths of 1,205 people, mostly civilians, according to an AFP tally based on official Israeli figures, which also includes hostages killed in captivity.