Israeli forces expanded their operations in the Gaza Strip on Monday, while Qatari mediators reported making progress toward a deal to release some of the 240 hostages held by Hamas.
Israel has issued evacuation warnings to residents of Gaza's largest refugee camp, Jabalia and a nearby coastal camp, stating that the military is "expanding its operational activities in additional neighborhoods ... of the Gaza Strip."
After Sunday's intense bombardment, columns of smoke were seen rising from Jabalia.
A Hamas health official reported that more than 80 people were killed in twin strikes on Jabalia on Saturday, including at a U.N. school sheltering displaced people.
Social media videos verified by Agence France-Presse (AFP) showed bodies covered in blood and dust on the floor of a building, where mattresses had been wedged under school tables.
Israel's military has stated that Jabalia is among the areas of focus as they "target Hamas infrastructure."
U.N. rights chief Volker Turk condemned the purported strike on the school as "horrifying," emphasizing that "the horrendous events of the past 48 hours in Gaza beggar belief."
On Monday, Palestinian News Agency (Wafa) reported that the Indonesian hospital near Jabalia had also come under shelling.
Israel launched its offensive against Hamas after a wave of brutal cross-border raids on Oct. 7 left 1,200 people dead, the majority of them civilians.
The Hamas government claims that the death toll from Israel's aerial bombardment and ground operations in Gaza has reached 13,000, including thousands of children.
Six weeks into the war, Israel is facing intense international pressure to justify its actions.
Israeli officials have warned that the "window of legitimacy" for the war to rout Hamas may be closing.
Chinese Foreign Minister Wang Yi on Monday called for urgent action to stop the "humanitarian disaster" unfolding in Gaza.
Israel presented what it said was evidence that Hamas members used Gaza's largest hospital, Al-Shifa, to hide foreign hostages and mask underground tunnels.
The Israeli military released CCTV footage from Oct. 7, showing two male hostages from Nepal and Thailand being brought into the hospital.
Israel also accused the Palestinian group of executing a 19-year-old Israeli soldier, Noa Marciano, at Al-Shifa, presenting images of what it said was a 55-meter-long underground tunnel under the hospital.
Over the weekend, hundreds of people fled Al-Shifa Hospital on foot as explosions were heard around the complex.
The WHO on Sunday said it evacuated 31 premature babies from the facility.
Al-Shifa's head of surgery, Marwan Abu Sada, reported that Israeli troops were still in the hospital, which was surrounded by tanks.
"I heard at least two explosions since this morning," he said on Sunday.
Other doctors said the troops were going from building to building, detonating explosives on the ground floors and hospital basements and searching for Hamas tunnels.
Israel has vowed to eradicate Hamas and free around 240 people taken hostage by the group, most of them Israeli citizens but also dozens of foreigners.
On Sunday, Qatari mediators said they were inching closer to a deal to free some of the hostages held by Hamas in Gaza.
Qatar's prime minister stated that efforts to bring hostages "safely back to their homes" in return for a temporary cease-fire were now within reach.
The hostages include infants, teens and pensioners. U.S. Deputy National Security Adviser Jon Finer stated that negotiators were "closer than we have been in quite some time" to securing a deal.