Israeli soldiers found a tunnel shaft used by Hamas militants at Gaza's Al Shifa hospital, the army said, while the U.N. voiced concern no aid would be delivered to Palestinians on Friday via the Rafah crossing with Egypt.

The army released a video it said showed a tunnel entrance in an outdoor area of Al Shifa, Gaza's biggest hospital.

The video, which Reuters could not immediately verify, showed a deep hole in the ground, littered with and surrounded by concrete and wood rubble and sand. It appeared the area had been excavated; a bulldozer appeared in the background.

The army said its troops also found a vehicle in the hospital containing a large number of weapons.

Hamas said in a statement late on Thursday that claims by the Pentagon and U.S. State Department that the group uses Al Shifa for military purposes "is a repetition of a blatantly false narrative, demonstrated by the weak and ridiculous performances of the occupation army spokesman."

The United States is confident in an assessment from its own intelligence agencies on Hamas activities in Al Shifa hospital and will neither share nor elaborate on it, White House spokesperson John Kirby said on Thursday.

The two telecoms companies in Gaza said all energy sources supplying the network had run out and therefore all services in the territory were down. Israel refuses fuel imports, saying Hamas could use them for military purposes.

With communications out and in the absence of fuel, the U.N. agency for Palestinian refugees, UNRWA, said it was impossible to coordinate humanitarian aid truck convoys.

"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.

As of late Thursday night, there was no further word from the companies, Paltel and Jawwal, whose internet, mobile phone and landline networks remained inoperable.

Palestinian civilians have borne the brunt of Israel's weeks-long military campaign in retaliation for an Oct. 7 attack by Hamas that Israel says killed 1,200 people, mostly civilians.

Gaza health authorities deemed reliable by the United Nations say at least 11,500 people have been confirmed killed in an Israeli bombardment and ground invasion - more than 4,700 of them children.

The Israeli military's chief of staff said Israel was close to destroying Hamas' military system in the northern Gaza Strip and there were signs the army was taking its campaign to other parts of the enclave of 2.3 million people.

Israel distributed pamphlets telling civilians to leave four towns in southern Gaza, areas Gazans had been previously told would be safe.

GAZA HOSPITALS AT CRUX OF GLOBAL DEBATE

Israeli officials said Hamas held some of the 240 hostages taken by gunmen on Oct. 7 in the hospital complex. The body of a woman hostage was recovered by troops in a building near Al Shifa on Thursday, the army said.

Military equipment including Kalashnikov rifles and rocket-propelled grenades were also found in the building, it said.

Human Rights Watch said 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 said.

EU foreign policy chief Josep Borrell, on his first visit to Israel since the Oct. 7 Hamas attack, called on Israel to do more to protect civilians in Gaza.

"I understand your rage but let me ask you not to be consumed by rage," Borrell said. Israeli Foreign Minister Eli Cohen said Hamas was to blame not only for the Oct. 7 attack but also for the current plight of Palestinians in Gaza.