An Israeli airstrike on a central Gaza school being used as a shelter for displaced Palestinians has killed 14 people, the Hamas-run territory’s civil defence agency has said, with the UN reporting that six of its staff were among the dead.

The UN Palestinian refugee agency, Unrwa, said the attack was the highest death toll among its staff in a single incident. Two airstrikes hit the school and its surroundings in Nuseirat, it said.

“Among those killed was the manager of the Unrwa shelter and other team members providing assistance to displaced people,” the UN agency said on X.

Earlier, Israel’s 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 the outcome or the identities of those targeted.

The Hamas government media office said about 5,000 displaced people were sheltering at the school when it was hit on Wednesday.

Unrwa said in its statement: “This school has been hit five times since the war began. It is home to about 12,000 displaced people, mainly women and children.”

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

Wednesday’s strike on the al-Jaouni school in the Nuseirat refugee camp injured at least 18 others, local health officials told the Associated Press.

An IDF spokesperson said that prior to the attack “a series of measures were taken to reduce the likelihood of civilian casualties, including the use of precision weapons, the use of aerial imagery, and additional intelligence.”

UN secretary-general António Guterres said late on Wednesday that “what’s happening in Gaza is totally unacceptable.”

“Six of our @UNRWA colleagues are among those killed,” Guterres said in a post on X.

The Israeli military says it takes steps to reduce the risk of harm to civilians and that at least a third of the Palestinian fatalities in Gaza are militants. It accuses Hamas of using Palestinian civilians as human shields, which Hamas denies.

Earlier on Wednesday, a strike hit a home near the southern Gaza city of Khan Younis, killing 11 people, including six brothers and sisters ranging from 21 months to 21 years old, according to the European hospital, which received the casualties.

The war in Gaza is now into its 11th month, with more than 41,000 Palestinians killed according to the territory’s health ministry and international efforts to mediate a ceasefire between Israel and the Hamas militant group repeatedly stalled. The war was triggered on 7 October when Hamas attacked Israel, killing 1,200 people and taking about 250 hostages.

Hamas said on Wednesday that its negotiators had reiterated its readiness to implement an “immediate” ceasefire with Israel in Gaza based on a previous US proposal without new conditions from any party.

The group said in a statement that their negotiation team, led by senior official Khalil al-Hayya, had met mediators in Doha to discuss the latest developments in Gaza.

CIA director William Burns, who is also the chief US negotiator on Gaza, said on Saturday that a more detailed ceasefire proposal would be made in the next several days.

The previous proposal put forward by president Joe Biden in June laid out a three-phase ceasefire in return for the release of Israeli hostages. However lingering issues, including control of the Philadelphi corridor, a narrow stretch of land on Gaza’s border with Egypt, remain.

Israeli prime minister Benjamin Netanyahu has defied protests at home and criticism from Biden by vowing that Israel would not relinquish control over the strategic corridor.

In Gaza, a strike late on Tuesday on a home in the urban Jabaliya refugee camp in the north of the territory killed nine people, including six women and children, according to the Health Ministry and the civil defence.

Israel’s military meanwhile reported the deaths of two soldiers late on Tuesday when an army helicopter crashed in the area of Gaza’s southern city of Rafah. The military announced on Wednesday that the helicopter had crashed while landing and that another eight soldiers were injured.

The aircraft had been on a “life-saving operation” to evacuate a wounded soldier when it crashed, Maj Gen Tomer Bar said in a statement.

“An investigative committee has been appointed to investigate the details of the crash,” he said, and called it an “operational accident”.

With Reuters, the Associated Press and Agence France-Presse