Palestinians gather to receive the humanitarian aid supplies airdropped into Khan Younis, Gaza, on 28 May. Photograph: Ashraf Amra/Anadolu/Getty Images

Fayiz Abu Ataya was born into war and knew nothing else. Over his first and only spring, in a town stalked by hunger, he wasted away to a shadow of a child, skin stretched painfully over jutting bones.

In seven months of life, he had little time to make a mark beyond the family who loved him. But when his death from malnutrition was reported last week, it sounded a warning around the world about a rapidly deepening crisis in central and southern Gaza, triggered by the Israeli military operation in the southern town of Rafah.

At least 30 child victims of malnutrition have been recorded in Gaza, but almost all died in the north, until recently the area with the most extreme shortages of food and medical care, where a top US aid official said famine had taken hold in some areas.

The arrival of Israeli troops in Rafah in May shifted the grim calculus of threat in the strip.

“The ongoing situation in Rafah is a disaster for children,” said Jonathan Crickx, chief of communication for Unicef in Palestine. “If nutrition supplies, especially ready-to-use therapeutic food, used to address malnutrition among children, cannot be distributed, the treatment of more than 3,000 children with acute malnutrition will be interrupted.”

The body of Fayiz Abu Ataya, who died due to malnutrition, is brought to Al-Aqsa Martyrs Hospital in Deir al Balah, Gaza, on 30 May. Photograph: Anadolu/Getty Images

For months, northern Gaza, cut off by an Israeli military cordon, had been hungrier than the south. Aid mostly trickled into the strip through the Rafah crossing with Egypt, and the Kerem Shalom gateway from Israel.

Now the border with Egypt is controlled by Israeli troops, the Rafah crossing is closed, and fighting has choked shipments of humanitarian aid through Kerem Shalom. The supply of humanitarian aid into Gaza overall has dropped by two-thirds since 7 May, when the operation began, UN figures showed last week.

Much of the food still getting into Gaza is shipped to the north through new crossings, meaning the crisis there has eased, but people in the south are running out of supplies, the World Food Programme chief for Palestine said.

“[In the north,] it is a situation that has improved significantly from five weeks ago,” said Matthew Hollingworth. “On the other side, in the middle and in particular the south, what we’ve seen just since 7 May is the situation begin to deteriorate again.

“We’ve got a week or so before people will genuinely run out of all assistance they were able to receive through April and the start of May.”

A floating pier built by the US and able to funnel shipments either north or south was damaged by bad weather and is expected to be out of operation for several more days at least.

An Israeli missile strike that sparked a blaze among crowded refugee tents last weekend, killing at least 45 people, was a grim demonstration of the urgent threat to civilians from bombs and bullets during the operation in Gaza.

Collapsing access to food and medical care may be a slower-motion tragedy, but one that threatens almost everyone in the south of the enclave now. Twenty international aid agencies warned last week that “the unpredictable trickle of aid into Gaza has created a mirage of improved access while the humanitarian response is in reality on the verge of collapse”.

They now fear “an acceleration in deaths from starvation, disease and denied medical assistance”, the groups, including Médecins Sans Frontières, Oxfam and Save the Children said in a joint statement.

On Saturday, another child death from malnutrition was recorded in Deir al Balah, a 13-year-old. Those two losses in a week are probably an indicator of a much greater emergency.

“In similar crises around the world, according to Unicef experience, usually children don’t die from malnutrition and dehydration in hospitals, they die at home, in the street or where they have taken shelter,” Crickx said. “This means reported deaths of children from malnutrition only show part of the whole toll. There is a reasonable concern that in Gaza too, there are significant numbers of children affected by malnutrition who are not represented in reported figures.”

Most children under five in Gaza are spending entire days without eating anything at all. A snapshot survey, looking at food access over three days in May, found that 85% spent at least one day without food, WHO spokeswoman Margaret Harris said.

A view of the floating pier, set up by the US to facilitate delivery of humanitarian aid to Palestinians, after it was suspended due to adverse weather conditions and rising sea levels in Gaza City on 27 May. Photograph: Anadolu/Getty Images

Lack of food is not the only risk. Lack of clean water and sanitation also means that children are at far greater risk of getting infectious diseases, which are particularly dangerous to the very young. The closure of most hospitals and clinics, damage to those still operating and severe overcrowding means parents struggle to access even basic care for gastrointestinal illness, let alone the close monitoring and treatment needed to recover from malnutrition.

Save the Children said there is no longer any route for them to carry out medical evacuations of children who need urgent treatment outside Gaza.

After heavy pressure over aid shortages from the US, Israel’s closest ally, and a ruling from the international court of justice that Israel must do more to address the humanitarian catastrophe, the country has opened new crossings for aid.

Israeli authorities say there is no limit on the supplies that can be sent into Gaza, blame hunger on logistics failures by humanitarian groups, and give figures for trucks of aid into Gaza that are higher than UN data.

“Israel is committed to abide by our obligations according to international law and our stated policy that there is no limit on the amount of humanitarian aid that we are willing to accept,” said Shimon Freedman, spokesman for Cogat, the Israeli body responsible for humanitarian coordination.

He said the average daily number of trucks into Gaza had increased in May to around 350 compared with around 300 in April, adding: “I know that there have been other numbers publicised by different organisations, but those numbers do not represent the full picture.”

Humanitarians have described the focus on truck numbers as misleading because there is no standard for either truck size, how to count full or partial loads, or where they should be counted. Israel counts trucks passing into Kerem Shalom, including some that are not fully loaded, while the UN counts only those arriving in Gaza fully loaded.

“It’s almost a fool’s game to do the truck counting,” OCHA spokesman Jens Laerke said on Friday. The focus instead should be on what supplies are getting into Gaza, and then reaching those in need, he added.

Humanitarian groups say a set of security requirements and logistical challenges – which may not seem insurmountable in isolation –mean it is practically impossible to deliver sufficient aid. These include capacity for Israeli security checks at all borders, to getting permission from the military to move around inside Gaza. The Norwegian Refugee Council described efforts to reach the most vulnerable people in Gaza as “a giant game of snakes and ladders”, in which staff make “very small steps forward and then end up back at square one”.

“If humanitarian supplies are allowed into Gaza, we might not have fuel with which to transport them. When we have fuel, we may not have cash with which to pay for trucks,” it said. “The day we can pay for trucks, the roads to the warehouse could be too dangerous to travel. And if we can get to the warehouse, the staff on whom we depend to load cargo could have fled when the explosions came too close.”

In March, a coalition of aid groups had warned that famine was imminent in northern Gaza with people suffering “catastrophic levels of hunger”.

The Integrated Food Security Phase Classification (IPC) group said southern parts of Gaza would also face a risk of famine in a “worst-case scenario”, which included the invasion of Rafah now underway.

The WFP’s Hollingworth called for urgent action to prevent that becoming a reality. “By the time famine is declared it’s already too late, there are already too many deaths,” he said. “We are not necessarily too late in the south and centre of Gaza, but we have to act now.”

Emma Graham-Harrison in Kerem Shalom

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