An Israeli air strike on a UN school packed with hundreds of displaced people in central Gaza has killed more than 20 people, local residents say.

The Israeli military said it carried out a strike on a UN school that housed a "Hamas compound".

Local journalists told the BBC that an Israeli warplane fired two missiles at classrooms on the top floor of the school in the Nuseirat refugee camp.

The Hamas media office said at least 27 people were killed and accused Israel of committing a "horrific massacre".

Ambulances and rescue teams have been rushing the wounded and dead to a nearby hospital.

Footage on social media showed destroyed classrooms and dead bodies wrapped in shrouds at a morgue.

"Enough war! We have been displaced dozens of times. They killed our children while they were sleeping," a woman injured in the attack screamed in one video.

Ismail al-Thawabta, director of the Hamas media office, rejected Israel's claims that the UN school had hidden a Hamas command post.

"The occupation uses ... false fabricated stories to justify the brutal crime it conducted against dozens of displaced people," he told Reuters.

The Israel Defense Forces (IDF) said jets had conducted a "precise strike on a Hamas compound embedded inside an UNRWA school in the area of Nuseirat".

The IDF statement said it had "eliminated" Hamas and Islamic Jihad "terrorists" who took part in the 7 October attack on southern Israel, when around 1,200 people were killed and 251 others were taken hostage.

At least 36,580 people have been killed in Gaza since then, according to the territory's Hamas-run health ministry.

The IDF said it had taken steps before the air strike to "reduce the risk of harming uninvolved civilians".

Earlier, the Israeli military said it had taken “operational control” over eastern areas of Bureij refugee camp and the town of Deir al-Balah in central Gaza, as dozens of Palestinians were reported killed.

On Wednesday morning, the military said troops backed by air strikes had begun an operation against “terrorists and terrorist infrastructure above and below ground".

Residents reported intense bombardment and the charity Médecins Sans Frontières (MSF) said at least 70 dead people - the majority women and children - had been brought to a local hospital since Tuesday.

MSF said its medical team on the ground had described the situation at Deir al-Balah's al-Aqsa hospital - one of the only remaining functional health facilities in central Gaza - as "apocalyptic".

The charity said women and children made up the majority of the 70 dead people and 300 wounded, brought to hospital over the past 24 hours, and that many patients were suffering from severe burns, shrapnel wounds, fractures and other traumatic injuries.

"The odour of blood when I entered the emergency room [this morning] was just overwhelming. People are lying on the floor. People are lying outside... bodies being brought in white plastic bags. The families standing over them and praying," MSF medical referent Karin Huster said in an audio message.

"It's just an emotionally overwhelming situation. It's impossible for anyone to cope."