Three children and one woman were killed when a sand embankment collapsed onto tents in central Gaza following heavy rain, the Hamas-run health ministry says.
Five injured people were also reportedly rescued after the incident on Sunday night at a camp for displaced families south of Deir al-Balah.
Videos showed men using phone torches to search for survivors beneath boulders, sand and collapsed tents.
The Civil Defence service, which operates under the Hamas-run interior ministry, said the "humanitarian tragedy" should prompt urgent action by international organisations to provide safe shelters for displaced people and move tents away from sandy areas, slopes and locations at risk of collapse.
Torrential rain on Saturday reportedly flooded tens of thousands of tents across Gaza, leaving many Palestinians without a dry place to sleep.
The Civil Defence said water levels reached up to 1.5m (4.9ft) in some places and that its first responders were able to respond to only 10% of the 2,100 distress calls they received.
"Protecting the lives of displaced people is an urgent humanitarian responsibility. Their tents must not become death traps beneath sand and rainwater," it warned.
The Civil Defence initially reported on Sunday that three children and two women were killed when the sand embankment collapsed. But the health ministry said on Monday morning that only one woman was among the dead.
Mustafa al-Masri told the BBC that he and other rescuers had used their bare hands to dig the victims and survivors out of the sand and rubble.
"It was extremely difficult. This mound was huge and wide. It collapsed onto the tent, and we didn't know what to do," he said.
"When we got here, we, along with the young men from the camp, pulled them out with our own hands. We pulled out the children and the woman."
"Their father arrived shouting, 'My children, my children, my children, my children.' We pulled his children out, put them in the ambulance, and took them to the hospital."
Masri added that he had been displaced from the northern town of Beit Hanoun but had stayed in central Gaza because there was "nowhere for me to return to".
"We went out looking around, searching through the open areas and hills, but I couldn't find any place other than this area that felt suitable for me."
The International Organization for Migration's regional crisis co-ordinator, Karl Baker, told the BBC from Gaza that the territory's 2.1 million population was confined to only 30% of its total area and that many people were "unfortunately living in areas which would not be normal if we were not in this time of conflict".
He said the UN agency and its partners were trying to make sure there were enough tents and tarpaulins, as well as improved drainage in camps, to help them get through the winter.
However, he warned that aid currently getting into Gaza was not sufficient to meet the demands of the population, describing it as "the very smallest of Band-Aids [plasters]".
"We need more support, in-kind donations. We need funding in order to help the communities to help themselves," he said. "We need a lot more to happen."
UN agencies have called on Israeli authorities to allow in the specialist equipment and materials required to improve living conditions for displaced families.
Cogat, the Israeli military body tasked with co-ordinating deliveries, said on Sunday that more than 91,000 tents, 12 vacuum trucks for waste removal, and fuel and engine oil for pumping facilities have been delivered since the start of the "Gaza Winterization Plan".
But it added that Israel would not permit the entry of equipment that could be used for military purposes by Hamas and other Palestinian armed groups.
An estimated 80% of all structures in Gaza have been destroyed or damaged during the war between Israel and Hamas, according to the UN.
More than 1.9 million people have been displaced, many of them multiple times, and 1.2 million of them are currently living in tents or makeshift shelters, it says.
The UN has warned that the humanitarian situation in Gaza remains dire despite the ceasefire agreed in October 2025, as Israeli air strikes and other attacks continue to hit populated areas, causing casualties and property damage and driving further displacement.
The Gaza war was triggered by the Hamas-led attack on southern Israel on 7 October 2023, when about 1,200 people were killed and 251 others were taken hostage.
Since then, more than 74,640 people have been killed in Gaza, according to the territory's health ministry, whose figures are considered reliable by the UN.
