By Nidal al-Mughrabi and Ari Rabinovitch
GAZA/JERUSALEM (Reuters) -Palestinian medics said on Thursday they are increasingly afraid for the lives of hundreds of patients and medical staff at Gaza's biggest hospital, cut off from all links to the outside world for more than a day after Israeli forces entered.
Israel said its commandos were still searching through Al Shifa hospital on Thursday, more than a day after they entered its grounds as part of an offensive Israel says aims to wipe out Hamas militants in the Palestinian enclave.
Israel believes a vast underground Hamas command headquarters was operating in tunnels beneath the hospital and on Thursday night the military said troops had found a tunnel shaft and vehicle with weapons inside the hospital complex.
"In the Shifa Hospital, IDF troops found an operational tunnel shaft and a vehicle containing a large number of weapons," the military said, using the acronym for the Israel Defense Forces.
The military released videos and photographs which it said showed the tunnel shaft and weapons.
It also said the body of an Israeli woman, one of around 240 hostages taken by Hamas gunmen when they stormed into southern Israel on Oct. 7, was recovered by troops in a building near the hospital.
Military equipment including Kalashnikov rifles and rocket-propelled grenades were also found in the building, it said.
Human Rights Watch cautioned that hospitals have special protections under international humanitarian law.
"Hospitals only lose those protections if it can be shown that harmful acts have been carried out from the premises," the watchdog's U.N. Director Louis Charbonneau told Reuters.
The director of Al Shifa Complex, Muhammad Abu Salamiya, said the hospital had been "under occupation authority for 48 hours and every minute that passes" more patients will die.
"We are waiting for slow death," he told Al Jazeera TV.
Gaza's health ministry said Israeli soldiers had removed bodies from the hospital grounds and destroyed cars parked there, but they were not letting staff or patients leave.
Ministry spokesman Ashraf Al-Qidra said there was no water, food or baby milk in Shifa, which was packed with 650 patients and about 7,000 people displaced by weeks of Israeli air strikes and artillery bombardments.
He demanded that the Israeli troops leave.
Medics have previously said dozens of patients including three premature babies had died from of a lack of fuel and basic supplies during a days-long siege.
UNRWA OPERATIONS 'STRANGLED'
Elsewhere, Israel ordered civilians to leave four towns in the southern part of the Gaza Strip on Thursday, raising fears war could spread to areas where it had told people they would be safe.
Israeli Defence Minister Yoav Gallant said in a statement Israeli forces had cleared the entire west part of Gaza City and that the "next stage has begun". The Israeli military's chief of staff said Israel was close to destroying Hamas's military system in the northern Gaza Strip.
"We will complete it," said Lieutenant-General Herzi Halevi.
Humanitarian agencies issued some of their direst warnings about the harm Israel's military campaign in Gaza was causing to civilians since it began retaliation against Hamas for its rampage in southern Israel.
The World Food Programme (WFP) said the Gaza Strip faced widespread hunger, with supplies of food and water almost exhausted.
"With winter fast approaching, unsafe and overcrowded shelters, and the lack of clean water, civilians are facing the immediate possibility of starvation," said WFP Executive Director Cindy McCain.
The head of the U.N. Palestinian refugee agency (UNRWA) said he believed there was a deliberate attempt to "strangle" its humanitarian work in Gaza, warning the agency may have to entirely suspend its operations due to a lack of fuel.
Israel refuses fuel imports, saying they could be used by Hamas for military purposes.
"If the fuel does not come in, people will start to die because of the lack of fuel. Exactly as from when, I don’t know. But it will be sooner rather than later," said UNRWA Commissioner-General Philippe Lazzarini.
Gaza's main telecommunications companies, Paltel and Jawwal, said all telecom services in Gaza had gone down, as all energy sources supplying the network had run out.
Reuters journalists have been unable to reach anyone inside Shifa hospital for more than 24 hours.
The World Health Organization said it was trying to arrange a medical evacuation of patients from Shifa, but was hindered by security concerns and the inability to communicate with anyone there.
All hospitals in northern Gaza have effectively been shut down by Israeli forces, who have ordered the evacuation of the entire northern part of the enclave, home to more than half its 2.3 million people.
At the Indonesian Hospital in Gaza, about 45 patients who need urgent surgery have been left in the reception area, hospital chief Atef al-Kahlout told al Jazeera.
Hamas fighters burst through the fence around Gaza on Oct. 7 in an assault that Israel says killed 1,200 people in the deadliest day in its history.
Israel has pounded Gaza with air strikes and cut off food and fuel. Gaza health authorities deemed reliable by the United Nations say more than 11,000 people have been confirmed killed, more than 40% of them children.
(Reporting by Nidal al-Mughrabi in Gaza and Emily Rose and Ari Rabinovitch in Jerusalem; Writing by Peter Graff and Nick Macfie, Editing by Angus MacSwan and Toby Chopra)