DEIR AL BALAH, Gaza Strip (AP) — A premature baby squirms inside a glass incubator in the neonatal ward of al-Aqsa Hospital in the central Gaza Strip. He cries out as intravenous lines are connected to his tiny body. A ventilator helps him breathe as a catheter delivers medication and monitors flash his fragile vital signs.

His life hinges on the constant flow of electricity, which is in danger of running out imminently unless the hospital can get more fuel for its generators. Once the generators stop, hospital director Iyad Abu Zahar fears that the babies in the ward, unable to breathe on their own, will perish.

“The responsibility on us is huge,” he said.

Doctors treating premature babies across Gaza are grappling with similar fears. At least 130 premature babies are at “grave risk” across six neonatal units, aid workers said. The dangerous fuel shortages are caused by the Israeli blockade of Gaza, which started — along with airstrikes — after Hamas militants attacked Israeli towns on October 7.

At least 50,000 pregnant women in Gaza are unable to access essential health services, and some 5,500 are due to give birth in the coming month, according to the World Health Organization.

At least seven of the almost 30 hospitals have been forced to shut down due to damage from relentless Israeli strikes and lack of power, water and other supplies. Doctors in the remaining hospitals said they are on the brink. The UN agency for Palestinian refugees said Sunday it has enough fuel to last three days to serve critical needs.

“The world cannot simply look on as these babies are killed by the siege on Gaza … A failure to act is to sentence these babies to death,” said Melanie Ward, chief executive of the Medical Aid for Palestinians aid group.

None of the 20 aid trucks that crossed into Gaza on Saturday, the first since the siege was imposed, contained fuel, amid Israeli fears it will end up in Hamas’ hands. Limited fuel supplies inside Gaza were being sent to hospital generators.

Seven tankers took fuel from a UN depot on the Gaza side of the border, but it was unclear if any of that was destined for the hospitals.

But will eventually run out if more is not permitted to enter.

Tarik Jašarević, a WHO spokesman, said 150,000 liters (40,000 gallons) of fuel are required to offer basic services in Gaza’s five main hospitals.

Abu Zahar worries about how long his facility can hold out.

“If the generator stops, which we are expecting in the coming few hours due to the heavy demands of different departments in the hospital, the incubators in the intensive care unit will be in a very critical situation,” he said.

Guillemette Thomas, medical coordinator for Doctors Without Borders in the Palestinian territories, said some of the babies could die within hours, and others in a couple of days, if they don’t receive the special care and medication they urgently need.

“It’s sure that these babies are in danger,” she told The Associated Press. “It’s a real emergency to take care of these babies, as it is an emergency to take care of the population of Gaza who are suffering from these bombings since the past two weeks.”

The hospital must care for patients in northern and central Gaza since several hospitals shut down, he said, forcing it to more than double its patient capacity. That also puts a strain on the limited electricity.

Nesma al-Haj brought her newborn daughter to the hospital from Nuseirat, where she was recently displaced from northern Gaza, after she suffered from oxygen deprivation and extreme pain, she said.

The baby girl was born three days ago but soon developed complications. “The hospital is lacking in supplies,” she said, speaking from al-Aqsa. “We are afraid that if the situation gets worse, there won’t be any medicine left to treat our kids.”

The problems are exacerbated by the dirty water many have been forced to use since Israel cut off the water supply. Abu Zahar says mothers are mixing baby formula with the contaminated water to feed their infants. It has contributed to the rise in critical cases in the ward.

In the al-Awda Hospital, a private facility in northern Jabalia, up to 50 babies are born almost every day, said hospital director Ahmed Muhanna. The hospital received an evacuation order from the Israeli military, but continued to work.

“The situation is tragic in every sense of the word,” he said. “We have recorded a large deficit in emergency medicines and anesthetic,” as well as other medical supplies.

To ration dwindling supplies, Muhanna said all scheduled operations were stopped and the hospital devoted all its resources to emergencies and childbirths. Complex neo-natal cases are sent to al-Aqsa.

Al-Awda has enough fuel to last four days at most, Muhanna said. “We have appealed to many international institutions, the World Health Organization, to supply hospitals with fuel, but to no avail so far,” he said.

Thomas said women have already given birth in UN-run schools where tens of thousands of displaced people have sought shelter.

“These women are in danger, and the babies are in danger right now,” she said. “That’s a really critical situation.”