The US has told Israel it must be fully "transparent" over an air strike that reportedly killed at least 35 people at a central Gaza school packed with displaced people on Thursday morning.

Local journalists told the BBC a warplane had fired two missiles at classrooms on the top floor of the school in the Nuseirat urban refugee camp.

The Israeli military said it had conducted a "precise" strike on a "Hamas compound" in the school, but Gaza’s Hamas-run government media office denied the claim.

The US called on Israel to identify publicly the Hamas fighters it said it had killed - just as the Israeli military gave the names of nine of them.

Israel frequently identifies militants it targets in air strikes but it is rare for the US to urge it to do so.

The Israelis “told us there were 20 to 30 militants they were targeting [and] they’re going to release the names of those they believe they’ve killed, those militants”, US state department spokesperson Matthew Miller said.

“That is what they have said they would provide. We expect them to do that, as well as any other details that would shed light on this incident."

In a near-simultaneous news briefing, Israeli army spokesperson Daniel Hagari gave the names of nine Hamas and Islamic Jihad fighters he said had been killed in the strike. He said more would be identified after work to “verify the information”.

In Washington, Mr Miller said the US has seen reports that 14 children were killed in the strike.

"If that is accurate that 14 children were killed, those aren’t terrorists," he said.

"And so the government of Israel has said they are going to release more information about this strike... We expect them to be fully transparent in making that information public.”

The latest deaths come just a week after 45 people were killed in an Israeli strike in the Gazan city of Rafah.

The latest strike, local journalists and residents say, happened in the early hours of Thursday at al-Sardi school, which is in a south-eastern area of the densely populated, decades-old camp, where the UN agency for Palestinian refugees, Unrwa, provides services.

Videos shared on social media showed the destruction of several classrooms in one of the school's buildings, as well as bodies wrapped in white shrouds and blankets.

Dead and wounded people were rushed to the al-Aqsa Martyrs’ Hospital, in the nearby town of Deir al-Balah, which has been overwhelmed since the Israeli military began a new ground operation against Hamas in central Gaza this week.

The BBC is working to verify the details of the strike in Nuseirat camp. Reports on the exact number of dead have varied.

Gaza’s Hamas-run health ministry said 40 people had been killed, including 14 children and nine women, and 74 others had been injured.

Unrwa's commissioner-general, Philippe Lazzarini, said at least 35 people had been killed and many more had been injured. The agency’s director of communications, Juliette Touma, told the BBC the figures were coming from Unrwa "colleagues on the ground".

Witnesses described a scene of devastation following the strike.

“I was asleep when the incident occurred,” Udai Abu Elias, a man who was living at the school, told BBC Arabic.

"Suddenly we heard a loud explosion and shattered glass and debris from the building fell on us. Smoke filled the air and I couldn't see anything. I didn't expect to make it out alive. I heard someone calling for survivors to come out from under the rubble. I struggled to see as I stumbled over the bodies of the martyrs.”

Unrwa said 6,000 displaced people had been sheltering in the school complex at the time. Many schools and other UN facilities have been used as shelters by the 1.7 million people who have fled their homes during the war, which has lasted almost eight months.

UN Secretary General Antonio Guterres condemned the strike through a spokesperson, saying that UN premises must be "inviolable" and protected by "all parties" during conflicts.

In a statement, the Israel Defense Forces (IDF) said jets had conducted a "precise strike on a Hamas compound embedded inside" the school. An annotated aerial photograph highlighted classrooms on two upper floors of the building, which the IDF said were the “locations of the terrorists”.

US officials have continued to lobby for what President Joe Biden called an Israeli ceasefire proposal.

The three-part plan would begin with a six-week ceasefire in which the Israeli military would withdraw from populated areas of Gaza. There would also be a "surge" of humanitarian aid, as well as an exchange of some hostages for Palestinian prisoners.

The deal would eventually lead to a permanent "cessation of hostilities" and a major reconstruction plan for Gaza. Germany, France and Britain re-affirmed their support for the deal in a joint statement with the US on Thursday and called for "an enduring end to the crisis".

CIA Director William Burns met mediators from Egypt and Qatar in Doha on Thursday to discuss the plans, but senior Cairo officials told the Reuters news agency that there had been no sign of a breakthrough on the deal.

At least 36,470 people have been killed in Gaza in almost eight months of fighting, according to the Hamas-run health ministry.

Hamas killed about 1,200 people and took 251 others hostage during its 7 October attacks on southern Israel.

Additional reporting by Rushdi Abu Alouf in Istanbul and David Gritten in London.