The Israel Defense Forces (IDF) said its troops were operating in the southern Gaza city of Khan Younis Tuesday as top officials at the United Nations warned of an “apocalyptic” situation in war-torn Gaza with “no place safe to go” for civilians.

“Every time we think things cannot get any more apocalyptic in Gaza, they do,” said Martin Griffiths, the top UN emergency relief official, in a statement on Monday. “People are being ordered to move again, with little to survive on, forced to make one impossible choice after another,” he said.

“Such blatant disregard for basic humanity must stop,” he also said.

Israel has been intensifying its aerial bombardment of southern Gaza in pursuit of Palestinian militant group Hamas and said over the weekend that it will expand ground operations to the whole of the territory.

The chief of general staff of the IDF, Leutenant General Herzi Halevi, said its forces were “now encircling” Khan Younis. Halevi said that the IDF was now entering the “third phase of the ground operations,” though he did not specify what that meant.

The Commander of the IDF Southern Command, Major General Yaron Finkelman had earlier described it as “the most intense day since the beginning of the ground operation - in terms of terrorists killed, the number of firefights, and the use of firepower from the land and air.”

The Hamas-controlled Ministry of Health in Gaza said 108 people had been killed at the Kamal Adwan hospital in northern Gaza, with dozens more injured, after heavy explosions and gunfire rocked the facility.

A journalist inside the hospital, Mahmoud Al-Sabbah, sent CNN video Tuesday of about 30 bodies covered in white sheets in a courtyard at the hospital. Several more bodies were piled on a cart because, he said, ambulances were unable to operate in the area. It’s unclear how long the bodies had been there, but he said family members were trying to identify loved ones.

The IDF said Tuesday its troops had “completed the encirclement” of the Jabalia refugee camp. The camp, also in the north, has seen intensive Israeli military operations since the week-long pause in the conflict ended.

UN Secretary-General Antonio Guterres on Monday appealed to the IDF to spare civilians from more suffering. “Civilians – including health workers, journalists and UN personnel - and civilian infrastructure must be protected at all times,” Guterres’ statement said, noting that despite evacuation orders, “there is nowhere safe to go in Gaza.”

Overall, 15,800 Palestinians have been killed in Israeli attacks in Gaza since October 7, according to a report published Tuesday by the Palestinian Ministry of Health in Ramallah, which cites sources from the Hamas-controlled enclave.

Senior US officials have urged Israel to make its operations more surgical and deliberate to minimize civilian casualties. Vice President Kamala Harris told reporters on Sunday she believed “that they have listened.”

But one senior administration official told CNN that in private not everyone agrees with that assessment. They said did not feel comfortable using the word “receptive” to capture Israel’s response so far to the Biden administration’s advice on its military operations.

The White House is deeply concerned, this official said, about how Israel’s operations targeting southern Gaza would unfold. US officials’ recent conversations with their Israeli counterparts about not replicating in the southern part of the strip the devastation it caused in the north had been “hard,” “firm” and “direct,” they said.

Palestinian civilians have been told to flee large swaths of Gaza, with the IDF releasing QR codes that show several online maps detailing areas it deems unsafe. However it is unclear how many residents the warnings are reaching, given damage to the enclave’s telecommunications services and electricity shortages.

IDF spokesperson Jonathan Conricus told CNN Monday evening that the QR code system it has implemented in recent days to designate unsafe areas of Gaza is not perfect but is “the best thing that we can do.”

‘There is no safe area’

As of last week, 1.8 million people in Gaza were estimated to be internally displaced, according to the UN – roughly 80% of the population.

Dozens of Israeli armored vehicles are operating in southern Gaza, satellite images from Sunday provided by PlanetLabs to CNN showed.

The images, obtained by CNN Tuesday, show the vehicles to the west of Salah El-Din Street, Gaza’s main north-south route, roughly six kilometers north of central Khan Younis. Tracks on the ground visible in the images show the Israeli armored vehicles had driven to the location in a near-direct line from the Israel-Gaza border in the east.

Scores of wounded people could be seen in footage being taken from rubble, to hospitals in southern Gaza throughout Monday. One Reuters video showed a baby being rushed from a civilian car into Nasser Hospital in the southern city of Khan Younis. The 2-month-old lies on a stretcher, apparently unconscious, as doctors remove his clothes and connect him to an oxygen supply.

“They told us to leave Gaza, there’s a war in Gaza, so we left (the north) and came here to the south just like they asked. But this is what we’ve found in the south,” Ibrahim Esbeitan, the baby’s father said in the video, pointing at this child.

In Salah Al-Arja, in Rafah, residents were seen trying to rescue their loved ones from the rubble with their bare hands. “We were asleep and safe, they told us it was a safe area, Rafah and all, but at twenty past ten, they stuck it with barrels, destroying all the block, there were children, women, and martyrs,” an unnamed local resident told Reuters.

“There is no safe area, neither Rafah, nor Khan Younis, nor Gaza, nor Dier, they are all liars, they say it is a safe area, they let us seek refuge, they evacuated Khan Younis and Gaza and still they bomb.”

The Secretary General of the Norwegian Refugee Council, Jan Egeland, said Tuesday his non-governmental organization was forced to halt nearly all of its aid operations in Gaza.

He issued a strong statement arguing that the “pulverising of Gaza now ranks amongst the worst assaults on any civilian population in our time and age.”

The head of the UN Relief and Works Agency for Palestine Refugees, Philippe Lazzarini, also warned against “horrors” that could follow in the wake of Israel’s expanding military operation, noting that an additional 60,000 people are now seeking shelter in overcrowded UN facilities.

“The evacuation order pushes people to concentrate into what is less than one-third of the Gaza Strip. They need everything: food, water, shelter, and mostly safety. Roads to the south are clogged,” Lazzarini said Monday, noting that access to water is limited in Gaza.

To resupply humanitarian aid efforts in Gaza, 180 humanitarian aid trucks carrying food, water, shelter materials and medical supplies were sent to the Rafah crossing on Monday at the request of the US Administration and in coordination with Egypt, according to Israel’s Coordinator of Government Activities in the Territories. Two diesel fuel tankers were also sent from Egypt to aid agencies operating in the strip, it said.

Health system struggling

What remains of the health system and infrastructure in Gaza is far from sufficient for the battered population’s needs as it enters a third month of siege, experts say.

Eighteen of Gaza’s 36 hospitals are still functioning, but can only provide partial services, the World Health Organization (WHO) said on Monday, adding that the 12 operational hospitals in the south are “the backbone of the health system.”

A WHO team visiting Nasser Hospital said the conditions there were “catastrophic” amid a flood of patients on Monday. “The building and hospital grounds [are] grossly overcrowded with patients and displaced people seeking shelter,” the statement said. “The emergency ward is overflowing with patients…Many patients are being treated on the floor.”

In a voice message posted on Monday, UNICEF spokesperson James Elder also described harrowing conditions in Nasser Hospital rooms after a blast had hit less than 100 meters away.

“There must be a hundred people, children now have been woken up by the bombs and explosions,” Elder said as babies’ cries could be heard in the background.

“Parents just have that look of.. the feeling no parent ever wants to experience, which is helplessness,” he said.