The Nasser Hospital in Khan Younis, Gaza's second-largest, stopped working last week after a week-long Israeli siege followed by a raid, the U.N. agency said. WHO staff and other aid groups have so far evacuated a total of 32 critical patients including injured children and those with paralysis, but the agency is concerned for those left behind with supplies dwindling.
"WHO fears for the safety and well-being of the patients and health workers remaining in the hospital and warns that further disruption to lifesaving care for the sick and injured would lead to more deaths," the WHO said on the social media site X, saying those remaining included 130 patients and 15 medics.
Israel says Hamas, the Islamist group that has run Gaza since 2007, uses hospitals for cover. Hamas denies this and says Israel's allegations serve as a pretext to destroy the healthcare system.
The WHO's Tarik Jašarević told reporters in Geneva that WHO staff who were part of the rescue mission had to navigate through pitch-black corridors with flashlights to find patients against a backdrop of gunfire.
Help had to arrive on foot because a deep, muddy ditch near the site made the road impassable, the WHO said.
"It's very difficult to see these scenes of people just being cut off," he said, saying food supplies were limited. "It's heartbreaking to see that there are people in health facilities who are not able to be treated correctly," he said.
Efforts to transfer the remaining patients are continuing, WHO said. The site has no electricity or running water and medical waste and garbage are "creating a breeding ground for disease", it added.
Palestinian health authorities said the situation had reached a "catastrophic level" and that Israeli forces had effectively converted the site into a "military barracks".
At least eight patients have already died at the facility, mostly due to fuel shortages and oxygen shortages, Palestinian health authorities have said. They described the situation on Tuesday as "catastrophic" and said the lives of those remaining there are directly threatened.
The more than four-month-old war was triggered by a Hamas attack on southern Israel on Oct. 7 in which 1,200 people were killed and 253 taken hostage, according to Israel.
Intent on destroying Hamas, Israel has responded with an air and ground assault that according to the Gaza health ministry's tallies has killed 29,195 Palestinians and wounded more than 69,000.
The war has displaced most of the enclave's 2.3 million people and over 1 million of them are now living in U.N. shelters or in tents and cardboard boxes in the southernmost tip of the enclave, against the border with Egypt.
