Israel-Gaza updates: IDF says it exposed Hamas tunnel under Shifa Hospital

The U.S. has intelligence that shows Hamas has used hospitals in Gaza to support its military operations and hold hostages, National Security Council spokesperson John Kirby confirmed Tuesday.

"I can confirm for you that we have information that Hamas, and the Palestinian Islamic Jihad, used some hospitals in the Gaza Strip -- including Al-Shifa -- and tunnels underneath them to conceal and to support their military operations and to hold hostages," Kirby said during a gaggle on Air Force One.

Kirby said Hamas and the Palestinian Islamic Jihad operate a command and control node from Al-Shifa Hospital in Gaza City where "they have stored weapons there, and they're prepared to respond to an Israeli military operation against that facility."

Kirby said the information comes from a "variety" of intelligence sourcing.

He cautioned again that these actions by Hamas "do not lessen Israel's responsibilities to protect civilians in Gaza."

"This is something that we obviously are going to continue to have an active conversation with our counterparts about," he said.

During a Pentagon briefing Tuesday, deputy Pentagon press secretary Sabrina Singh described the information as an independent U.S. intelligence assessment and "newly downgraded information that we felt was important to get out today because there have been a lot of questions about the hospital and how Hamas operates."

Singh did not go into specifics on the intel but said "we feel very confident in our sourcing and what the intelligence community has gathered on this topic."

-ABC News' Justin Gomez and Luis Martinez

A fuel shortage has stalled aid deliveries from Egypt into the Gaza Strip, a Rafah border crossing official told ABC News on Tuesday.

"No aid got in today because [the United Nations Relief and Works Agency for Palestine Refugees] trucks have no fuel," Wael Abu Omar, the Palestinian spokesman for the Rafah border crossing, said.

The UNRWA, which is responsible for receiving and distributing humanitarian aid coming from Egypt in Gaza, said Monday its trucks ran out of fuel and it would not be able to to receive aid coming through Rafah on Tuesday.

Tuesday marks the first day no aid trucks crossed into Gaza through Egypt since Oct. 21 amid the war.

Earlier on Tuesday, the Palestine Red Crescent Society said it received the last convoy of trucks from Egypt on Monday, including 155 trucks, following the UNRWA's announcement.

-ABC News' Ayat Al-Tawy

A mass grave has been dug inside Al-Shifa Hospital in Gaza to bury dozens of corpses after Israeli forces banned the Red Cross from collecting the bodies, according to Dr. Munir Al-Bursh, the director general of the Palestinian Health Ministry.

"There are approximately 100 corpses lying on the hospital courtyard that have rotted and decomposed," Al-Bursh told Al-Hadath TV on Tuesday, speaking from inside the hospital, the largest in Gaza. "We are walking on worms and we fear there will be an epidemic."

Medical staff and people sheltering inside the medical complex have dug a "large hole" to bury the dead bodies, he said. Dozens of other bodies stored in refrigerators at the facility will also be buried in the mass grave, he said.

"Israel tanks are at the gates of the hospital and we are burying bodies under gunfire and with tanks around," Al-Bursh said.

The hospital ceased to function on Saturday after it ran out of fuel, and staff and health ministry officials inside say the facility has been under siege by Israeli forces for five days, with drones and snipers firing into it.

"We are trying to dig a mass grave to bury the martyrs inside Al-Shifa Hospital. Our efforts to remove the bodies of the martyrs from Al-Shifa complex have failed," said Dr. Youssef Abu Al-Rish, undersecretary of the Hamas-run Gaza Ministry of Health.

Israeli officials have said Hamas is operating a command center from under the hospital, something denied by Hamas.

-ABC News' Ayat Al-Tawy and Morgan Winsor

One of two humanitarian corridors that the Israeli military has temporarily opened in the Gaza Strip on Tuesday is less than 1.5 miles long, according to an executive officer of an Israeli battalion in charge of the route.

The officer told ABC News that the corridor is a 2-kilometer stretch of Salah al-Din, the main highway connecting the north and south of Gaza. He said his troops have come under sniper fire and that "there were casualties."

The Israeli military has distributed leaflets directing civilians in the north to routes that take them to the corridors, offering safe passage to evacuate to the south of the war-torn enclave within a designated window of time on Tuesday.

-ABC News' Matt Gutman, Becky Perlow and Juan Rentaria