LONDON (AP) — As concerns grow for patients stranded inside Gaza’s biggest hospital, experts warned that transporting vulnerable people, including babies, is a perilous proposition under even the best circumstances.

On Tuesday, Palestinian authorities proposed a supervised evacuation of Shifa Hospital, a sprawling complex that runs several city blocks in the heart of Gaza City. Hours later, Israeli forces raided the facility — further complicating the picture.

Dr Irwin Redlener of Columbia University in New York said that moving newborns and premature babies with health problems is fraught but possible with trained personnel, proper equipment and a transportation plan.

“Babies in incubators have complex health needs and there needs to be temperature control, hydration, medication for infections and breathing support,” said Redlener, a pediatrician and disaster response expert, who spoke before the raid.

Redlener said that when hospitals in New York were evacuated due to Superstorm Sandy in 2012, medical workers walked down numerous flights of stairs carrying babies to waiting ambulances and there were no known tragedies — at least among the infants.

The storm, which hit the most populous metro area in the US, killed dozens of other people after devastating coastline communities, knocking out power and setting neighbourhoods ablaze.

“They were able to do that because they had time to plan for that and all the proper resources were available,” he said. “It’s completely the opposite in Gaza right now.”

Shifa is the largest and best-equipped hospital in the strip with over 500 beds, an intensive care unit and services like dialysis. Since the war between Israel and Hamas erupted several weeks ago, the hospital has acted as a shelter for tens of thousands of residents fleeing their homes as the conflict escalated.

Now, however, the hospital is a central focus in the war. Israel says the facility is used by Hamas for military purposes, without providing visual evidence. Gaza health officials and Hamas deny that.

Hundreds of people — including medical workers, premature babies and other vulnerable patients — are trapped inside with dwindling supplies, no electricity and an uncertain path out.

Israeli forces raided the complex early Wednesday. The military said soldiers were accompanied by medical teams and had brought medical supplies and baby food as well as incubators and other equipment.

But health officials say supplies and extra equipment are not enough to save patients and ongoing fighting makes it almost impossible to safely move patients.

Dr Natalie Thurtle, deputy medical coordinator for Doctors Without Borders in Jerusalem, said that many patients have not had access to proper medical care for weeks and there was no guarantee they would survive any evacuation or make a good recovery.

Given the lack of electricity, any incubators would have to be battery- or self-powered, and Redlener said moving babies would require trained personnel.

“The trip should be fast, so they need to know where they’re going,” he said. “It is possible to safely transport people from accident sites after terrible disasters, but you need staff on the ambulances with the expertise to take care of very sick patients.”

The Health Ministry in the Hamas-run territory said 40 patients — including three babies — have died since Shifa’s emergency generator ran out of fuel on Saturday, and another 36 babies remain at risk of dying.

Last week, the World Health Organization said a dozen children with cancer or blood disorders were safely moved from the Gaza Strip to Egypt and Jordan so they could continue their treatment.

Dr Mohammed Obeid, a surgeon at Shifa Hospital with Doctors Without Borders, said there were about two dozen patients who had recently undergone surgery and were unable to walk.

“We don’t have ambulances to evacuate all of these patients,” Obeid said, adding he was unable to leave. “If I am not here or the other surgeon, who will take care of the patients?”

The International Committee of the Red Cross said it was in touch with the Health Ministry and other parties.

The Red Cross said it was “extremely concerned” about the situation at Shifa hospital, noting that hospitals are protected under international humanitarian law and must be spared from violence.

“Hospitals and medical facilities are meant to be humanitarian sanctuaries,” the organisation said in a statement.

Late Tuesday, the Palestinian Red Crescent aid group announced the evacuation of remaining patients, doctors and families from Al-Quds hospital, which is to the south of Shifa. Nebal Farsakh, spokesperson for the group, told The Associated Press earlier in the day that 300 people were still inside.