Israeli forces said on Thursday they had raided the biggest functioning hospital in Gaza as footage showed chaos, shouting and gunfire in dark corridors filled with dust and smoke.

Israel’s military called the raid on Nasser Hospital “precise and limited” and said it was based on information that Hamas militants were hiding and had kept hostages in the facility, with some bodies of captives possibly there.

Hamas called that lies.

Health authorities in the Hamas-run Palestinian enclave said Israel had forced out dozens of staff, patients, displaced people and families of medical staff sheltering in the hospital. Some 2,000 Palestinians arrived in the southern border city of Rafah overnight while others pushed north to Deir Al-Balah in central Gaza, they said.

The war began on Oct. 7 when Hamas sent fighters into Israel, killing 1,200 people, mostly civilians, and seizing 253 hostages according to Israeli tallies.

Israel’s air and ground offensive has since devastated tiny, crowded Gaza, killing 28,663 people, also mostly civilian, according to health authorities, and forcing nearly all its more than 2 million inhabitants from their homes.

In a new operation, the Israeli military said it carried out an air strike that killed a Hamas commander who had participated in the Oct. 7 attack. He had also held captive a female Israeli soldier who was executed by Hamas, the military said.

Separately, medical officials said an Israeli strike killed three Palestinians in a car in Gaza City. Their identities were not immediately clear.

The Israeli military said a soldier was killed in fighting in southern Gaza, bring its total losses since ground incursions began on Oct. 20 to 235.

The medical charity Medicins San Frontieres said Israel shelled Nasser Hospital in the early hours, despite having told medical staff and patients they could remain.

“Our medical staff have had to flee the hospital, leaving patients behind,” it said on social media platform X, adding a member of its staff was detained at an Israeli checkpoint set up to screen those leaving the compound.

Fighting at the hospital comes as Israel faces growing international pressure to show restraint, after vowing to press its offensive into Rafah, the last relatively safe place in Gaza.

Attacks that have destroyed the majority of Gaza’s medical facilities have caused particular concern, including Israeli raids on hospitals in other cities, shelling in the vicinity of hospitals and the targeting of ambulances.

As massive bombardment destroyed swathes of residential districts and forced most people from their homes, hospitals quickly became the focus for displaced people seeking shelter around buildings they thought more likely to be safe.

Israel accuses Hamas of regularly using hospitals, ambulances and other medical facilities for military purposes, and has aired footage taken by its troops that it says shows tunnels containing weapons below some hospitals.

The Israeli military said it apprehended various suspects at Nasser Hospital and that its operations there were continuing.

Senior Hamas official Sami Abu Zuhri said Israel was lying about Nasser as it had about other hospitals

Video shows hospital chaos

Speaking about the hospital raid, Israeli military spokesperson Rear Admiral Daniel Hagari said “this sensitive operation was prepared with precision and is being conducted by IDF special forces who underwent specified training”.

One objective of the operation was to ensure the hospital could continue treating Gazan patients and “we communicated this in a number of conversations we had with the hospital staff,” he said, adding there was no obligation to evacuate.

Gaza health ministry spokesperson Ashraf al-Qidra said the hospital would run out of fuel within the next 24 hours, threatening the lives of patients, including six in intensive care and three infants in the neonatal ward.

Hagari said Israel had arranged the transfer of medical supplies and fuel to the hospital in coordination with international organizations.

Videos that Reuters verified on Thursday as having been filmed inside Nasser Hospital - though it could not check when - showed chaos and terror.

Men walked through corridors using phone lights, with plaster dust swirling around and debris lying about, at one point wheeling a bed through a damaged area.

In one video, gunshots rang out and a doctor shouted: “Is there anyone still inside? There is gunfire, there is gunfire - heads down”.

Another man in a video said the Israeli army had surrounded the hospital and nobody could get out.

Mohammad al Moghrabi, who had been sheltering in the compound, said some people who attempted to leave on Wednesday were shot at and so returned to the hospital.

“This morning they said there was a safe passage, so we left, but it wasn’t safe. They approached us with a bulldozer and a tank, they insulted us and left us for four hours under the sun.”