Israeli tanks have taken up positions outside Al Shifa Hospital, Gaza City's main medical center, which Israel says sits atop of tunnels housing a headquarters for Hamas fighters who are using patients as shields.

Hamas denies the Israeli claim.

Israel launched its war against Hamas after the Islamist Palestinian group's Oct. 7 rampage into southern Israel. Around 1,200 people died in that attack and 240 were dragged to Gaza as hostages according to Israel's tally.

The armed wing of Hamas said it was ready to free up to 70 women and children held in Gaza in exchange for a five-day truce in the war, in which Gaza medical authorities say more than 11,000 people have been confirmed killed, about 40% children.

Roughly two-thirds of the densely populated Mediterranean strip have been made homeless by Israel's military campaign, in which it has ordered the northern half of Gaza evacuated.

Gaza health ministry spokesperson Ashraf Al-Qidra, who was inside Al Shifa hospital, on Monday said 32 patients had died in the previous three days, including three newborns, because of the siege of the hospital in northern Gaza and a lack of power.

The Israeli military said early on Tuesday it had "initiated a humanitarian effort to coordinate transfer of incubators" from Israel to Al Shifa but made clear none of the devices, often used to keep pre-mature newborns warm, had been received by the facility.

There was no immediate comment from Al Shifa or from Hamas.

At least 650 patients were still inside Al Shifa hospital, desperate to be evacuated to another medical facility.

In his first comments since the weekend's events, including patient deaths reported at Al Shifa, Biden said hospitals must be protected.

"My hope and expectation is that there will be less intrusive action relative to hospitals and we remain in contact with the Israelis," Biden told reporters at the White House on Monday.

"Also there is an effort to get this pause to deal with the release of prisoners and that's being negotiated, as well, with the Qataris ... being engaged," he added. "So I remain somewhat hopeful but hospitals must be protected."

Israel launched its campaign last month against Hamas, the Islamist group that runs the Gaza Strip and that is officially dedicated to the destruction of Israel, after Hamas militants invaded southern Israel killing civilians and soldiers.

Israel says Hamas uses hospitals for military purposes and Israel's military on Monday released video and photos of what it said were weapons the group stored in the basement of Rantissi hospital, a pediatric hospital specializing in cancer treatment.

HOSTAGES FOR CEASEFIRE?

Al-Qassam Brigades, the armed wing of Hamas, posted an audio recording on its Telegram channel saying the group was ready to release as many as 70 women and children hostages in return for a five-day ceasefire, an offer Israel is unlikely to embrace.

"We told the (Qatari) mediators that in a five-day truce, we can release 50 of them and the number could reach 70 due to the difficulty that the captives are held by different factions," said al-Qassam Brigades spokesman Abu Ubaida said, saying Israel had asked for 100 to be freed.

Israel, which effectively blockades Gaza, has rejected a ceasefire, arguing that Hamas would simply use it to regroup, but has permitted brief humanitarian "pauses" to allow food and other supplies to flow in and foreigners to flee.

White House national security adviser Jake Sullivan told reporters Washington would "like to see considerably longer pauses - days, not hours - in the context of a hostage release."

Speaking on condition of anonymity, another U.S. official said the release of dozens of hostages could lead to a several-day pause but said negotiations were extremely delicate.

There was also fighting on Monday at a second major hospital in northern Gaza, al-Quds, which has stopped functioning.

The Palestinian Red Crescent said there was heavy gunfire around the hospital and a convoy to evacuate patients and staff could not get through.

Israel said it killed "approximately 21 terrorists" at al-Quds in return fire after fighters shot from the hospital entrance. It released footage it said showed men at the hospital gate, one of whom appeared to carry a rocket-propelled grenade launcher.

Israel's military and security services also said they had killed a number of Hamas commanders and officials in the last day, including Mohammed Khamis Dababash, who they described as the group's former head of military intelligence.

Hamas media said more than 30 people were killed and scores injured in an Israeli airstrike on the Jabalia refugee camp in northern Gaza. An Israeli military spokesperson said the army was checking the report on Jabalia.