Smoke rises as displaced Palestinians take shelter at Al Shifa hospital, amid the ongoing conflict between Hamas and Israel, in Gaza City

U.S. President Joe Biden said hospitals in the Gaza Strip must be protected and he hoped for “less intrusive” action by Israel as Israeli tanks advanced to the gates of the besieged enclave’s main hospital.

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.

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.