NUSEIRAT REFUGEE CAMP, Gaza — The Gaza Strip runs on fuel. It powers the enclave’s hospitals, water pumps and taxis. It feeds the generators residents depend on for electricity and helps fire up the ovens at neighborhood bakeries.

But now Gaza, home to 2.3 million people, is almost out of fuel, nearly two weeks after Israel imposed a “full siege” on the territory and launched an air war against Hamas. The United Nations said Sunday that its relief agency for Palestinian refugees that operates in Gaza would run out of fuel in three days.

“Without fuel, there will be no water, no functioning hospitals and bakeries,” the agency’s commissioner general, Philippe Lazzarini, said in a statement. “Without fuel, aid will not reach those in desperate need.”

Israel announced its siege and military campaign after Hamas militants based in Gaza staged a surprise assault on nearby Israeli communities earlier this month. The rampage by Palestinian gunmen killed at least 1,400 people and led Israel to unleash firepower in Gaza, where more than 4,600 Palestinians have been killed, according to the Health Ministry.

On Saturday, the first aid convoy to Gaza since the war started entered the territory through the Rafah border crossing with Egypt. It included food, water and medicine but no fuel supplies, according to OCHA, the U.N. Office for the Coordination of Humanitarian Affairs. Another convoy of 14 trucks entered Gaza late on Sunday, the United Nations and the Israeli military said, also with no fuel.

The move to exclude fuel from the first delivery was an apparent concession to Israel, which worries that Hamas and other armed groups could divert it for military purposes. Israeli military spokesman Rear Adm. Daniel Hagari also accused Hamas last week of stealing fuel from U.N. facilities. Hamas representatives did not immediately respond to a request for comment.

The United Nations and others are in a “tough but fair discussion” with the Israeli government over an inspection regime for the aid going through Rafah, OCHA’s emergency relief coordinator, Martin Griffiths, told Reuters in an interview Saturday. He said a system for tracking the use of fuel was also being considered.

Palestinian militants use fuel to propel the rockets they manufacture and fire into Israel, as well as for vehicles the fighters drive during operations.

But fuel also helps power daily life here, as in elsewhere in the world, and keeps vital technology and machines working, from sanitation systems to cellphones to ambulances ferrying the wounded.

Gaza’s only functioning power plant shut down on Oct. 11, when it ran out of fuel, blanketing the territory in darkness after Israel cut off its supply. In Gaza, a lack of fuel can now mean the difference between life and death.

Health Ministry spokesman Ashraf al-Qudra warned Saturday that the failure to supply local hospitals with fuel was putting the lives of sick and injured patients at risk. The ministry has been reallocating limited amounts of fuel to hospitals to keep them open, OCHA said Saturday, and has asked people to donate their personal fuel supplies.

On Saturday in Nuseirat, a refugee camp in central Gaza, 53-year-old Mahmoud Musallam wandered in search of a place where he could charge his Nokia phone, which doubles as a night light.

He traveled with his family to Nuseirat from northern Gaza a few days ago, after the Israeli military warned more than 1 million residents in that part of the territory to leave ahead of an expected ground invasion. Musallam and his nine family members evacuated first by auto rickshaw and then by a donkey-led cart.

“We couldn’t find transportation due to the shortage of fuel,” said Musallam, adding that they took shelter in a U.N. school nearby. “And I don’t know where I’m going to stay tomorrow.”

Israel, when it first declared the siege, said it would not allow any food, fuel, water or power into Gaza until Hamas freed the hostages it took during its Oct. 7 attack.

“Humanitarian aid to Gaza? No electric switch will be turned on, no water tap will be opened and no fuel truck will enter until the Israeli abductees are returned home,” Israeli Energy Minister Israel Katz said in a statement on Oct. 12.

Under intense international pressure, including from President Joe Biden, Israeli Prime Minister Benjamin Netanyahu agreed to a deal with Egypt and the United Nations to allow food, water and medicine to enter through Rafah for civilians in southern Gaza.

Netanyahu’s office on Saturday said that it wanted aid to continue to enter Gaza through Rafah, on the “one condition” that it “must reach the people of Gaza and not be diverted to Hamas.”

For years, Israel, which controls most entry points into Gaza, has restricted the transfer of “dual-use” items to the territory, including construction materials, chemicals, machinery and spare parts, according to the Israeli rights group Gisha. Israel has banned some dual-use items outright and allowed others entry with special permits.

Israel has also limited or halted fuel supplies to Gaza in previous conflicts.

In August, before the recent outbreak of fighting, a total of 1,200 trucks carrying diesel, benzene and cooking gas entered Gaza, according to Tania Hary, Gisha’s executive director.

But since the Hamas attack, Israel has blocked fuel supplies for the territory. “It’s clearly a potentially dual-use item in their eyes,” said an official with knowledge of the negotiations over Gaza aid access. The person spoke on the condition of anonymity to discuss sensitive negotiations.

In Nuseirat, Sara Saftawi is staying with dozens of family members in a single apartment building, after she fled with her husband and toddler from their home in Beit Lahiya in northern Gaza. Their only power source is a group of solar panels, which she said provide about an hour of electricity each day.

Saftawi’s husband, she says, is a critical care doctor and still works some days at al-Shifa Hospital, Gaza’s largest medical complex. Fuel shortages there have forced many of the generators to shut down, and the power is now off in many departments, with doctors performing surgery using their cellphones or flashlights.

On Friday, her husband came home from the hospital and couldn’t eat, she said. The number of unidentified bodies was piling up at al-Shifa, he told her, and the stench was haunting him. Without the fuel needed to power the morgue’s refrigeration units, there was nowhere to store the dead.

Berger reported from Ramallah, West Bank, and Parker from Cairo.

previous coverage

• Gaza gets some aid — but no fuel — as power crisis upends lives