The World Health Organization's chief said they had lost contact Friday with staff at northern Gaza's last functioning hospital, after the Israeli army said it was operating in the area.
"Since this morning's reports of a raid on Kamal Adwan hospital in northern Gaza, we have lost touch with the personnel there. This development is deeply disturbing given the number of patients being served and people sheltering there," WHO director-general Tedros Adhanom Ghebreyesus said on X.
Tedros said the WHO and partner agencies had reached the hospital late on Wednesday night and managed to transfer 23 patients and 26 caregivers to the Palestinian territory's main Al-Shifa Hospital.
"Kamal Adwan Hospital has been overflowing with close to 200 patients -- a constant stream of horrific trauma cases. It is also full of hundreds of people seeking shelter," said Tedros.
"Accessing hospitals across Gaza is getting unbelievably harder and exposes our staff to unnecessary danger."
Gaza's health ministry has informed that hundreds of patients and staff were detained from the hospital.
"Israeli forces have stormed and are present inside Kamal Adwan Hospital" in the city of Jabalia, the ministry said in a statement on Friday.
"They are detaining hundreds of patients, medical staff and some displaced individuals from neighbouring areas who sought refuge in the hospital from continuous bombardment," it added.
Images circulated on social media showed Palestinian men and teenage boys, being lined up by the Israeli military, half-naked and handcuffed.
"More than 150 patients and staff, including medical and nursing teams, are besieged by the Israeli army inside Kamal Adwan Hospital in Jabalia Camp, northern Gaza Strip," Mahmud Bassal, spokesman for Gaza's civil defence agency, said.
"There has been no supply or provision of food, medicine, or essential medical supplies needed to save the lives of the injured and sick in the hospital," Gaza's health ministry said, calling the situation inside "catastrophic in every sense of the word".
Israel's operation in northern Gaza has been termed by many as an attempt at "ethnically cleansing" Palestinians.
Deploring Israel's attacks in northern Gaza, Jordan's foreign minister Ayman Safadi on Friday told US Secretary of State Antony Blinken Blinken to work towards ending the "ethnic cleansing" of Palestinians.
"We do see ethnic cleansing taking place, and that has got to stop,"Safadi said.
"We really stand at the brink of regional war now. The only path to save the region from that is for Israel to stop the aggressions on Gaza, on Lebanon, stop unilateral measures, illegal measures, in the West Bank, that is also pushing the situation to an abyss," he added.
Israel has killed at least 770 Palestinians in northern Gaza's Jabalia refugee camp in just 19 days.
According to Mahmud Bassal, the toll is expected to rise as there are people buried under the rubble.
Israel has so far killed at least 42,800 Palestinians including at least 17000 children and 11400 women since the beginning of its recent war on Gaza. It has also killed nearly 1,000 health workers and 220 UN workers in Gaza.
The UN rights chief Volker Turk on Friday warned that Israel's operations in northern Gaza could amount to "crimes against humanity."
"We are facing what could amount to atrocity crimes, including potentially extending to crimes against humanity."
He called on the world's leaders to act, stressing that all states are obligated under the Geneva Conventions to ensure respect for international humanitarian law.
His statement stressed the urgency of the situation, warning that "today the darkest moment of the Gaza conflict is unfolding in the north of the Strip, where the Israeli military is effectively subjecting an entire population to bombing, siege and risk of starvation".
"The bombing in North Gaza is non-stop," he said.
At the same time, "the Israeli military has ordered hundreds of thousands to move, with no guarantees of return. But there is no safe way to leave," he warned.
The UN rights chief cautioned that there was "extremely limited access to this part of Gaza, (and) next to no aid has reached the area in weeks, with unlawful restrictions remaining".
"Many are now facing starvation."
At the same time, he said, "the Israeli military is striking hospitals, and staff and patients have been killed and injured or forced to evacuate simultaneously".
(With inputs from AFP)