A stone-and-concrete tunnel shaft with a metal ladder on the grounds of Al-Shifa Hospital in northern Gaza on Thursday.Credit…Daniel Berehulak/The New York Times

The discovery at Al-Shifa Hospital did not seem to settle the question of whether Hamas has been using the complex to hide weapons and command centers, as Israel has said.

Israeli forces on Friday probed further into civilian infrastructure in northern Gaza for signs of a Hamas presence, announcing that they had found weapons at a school and guiding international reporters to a tunnel shaft on the grounds of the territory’s largest hospital.

As troops searched the hospital, Al-Shifa, for a third day, Israel announced that it would allow limited shipments of fuel to the enclave to avoid “epidemics” amid the wreckage of the territory.

Israel has been under intense international scrutiny to justify its incursions into Gazan hospitals, which are sheltering thousands of civilians in addition to the sick and wounded. On Thursday night, the Israeli military escorted journalists from The New York Times through a landscape of wartime destruction to a stone-and-concrete shaft on the grounds of Al-Shifa with a staircase descending into the earth — evidence, it said, of a Hamas military facility under the hospital.

But Col. Elad Tsury, commander of Israel’s Seventh Brigade, said military forces, fearing booby traps, had not ventured down the shaft at the hospital. He said it had been discovered under a pile of sand on the northern perimeter of the complex.

In a building next to the hospital, the military said on Friday, it had discovered the body of a second hostage taken by Hamas, Noa Marciano, 19, who had been a corporal in the Israeli army. The military also announced that it had killed Hamas terrorists found “hiding” in a school.

In order to enter Gaza, two reporters and a photographer for The Times were obliged to remain with Israeli troops for the duration of the visit. They agreed not to photograph most soldiers’ faces, landmarks, maps and certain details of weapons. The Times did not allow the Israeli military to screen its account before publication.

Israeli soldiers from the Seventh Brigade escorted journalists to view the tunnel shaft on the grounds of Al-Shifa Hospital in Gaza City on Thursday.Credit…Daniel Berehulak/The New York Times

The journalists were allowed to see only a portion of the sprawling Al-Shifa complex. The military refused to let the journalists explore the hospital or see or interview patients and medical staff in the facility, saying that it had not been fully secured and that Hamas combatants may still be there.

The discovery of the tunnel shaft at Al-Shifa did not seem to settle the question of whether Hamas, the armed Palestinian group that rules Gaza, has been using the hospital to hide weapons and command centers, as Israel has said.

That claim is central to Israel’s defense of its military campaign in Gaza, which has killed more than 11,000 people, according to Gazan health officials. Israeli officials say that the loss of life has been caused in part by Hamas’s decision to hide its military fortifications and command centers inside civilian infrastructure like Al-Shifa.

Despite the fact that the Israeli military has yet to show incontrovertible proof of a vast tunnel network, Prime Minister Benjamin Netanyahu said on Friday that the military had found proof of its allegations about the use of Al-Shifa. There were “a lot of terrorists there,” he said in a National Public Radio interview, but “they fled as our forces approached the hospital.”

“We found a lot of weapons — a lot,” he added. “We found a lot of ammunition. We found bombs. We found on level minus two a command and control center of Hamas, with military encoded encryption.”