Hospitals were overrun with scores of dead and injured Palestinians as Israeli forces stormed the main city in the southern Gaza Strip Tuesday.

In what appeared to be the biggest ground assault since a truce collapsed last week, residents said Israeli tanks had entered the eastern parts of Khan Younis for the first time, crossing from the Israeli border fence and advancing west.

Some took up positions inside the town of Bani Suhaila on Khan Younis' eastern outskirts, while others continued further and were stationed on the edge of a Qatari-funded housing development called Hamad City, residents said.

The Israelis, who seized the northern half of Gaza last month before pausing for the weeklong truce, say they are now extending their ground campaign to the rest of the enclave to fulfill their objective of eradicating Hamas.

"We're moving ahead with the second stage now. A second stage that is going to be difficult militarily," government spokesperson Eylon Levy told reporters in a briefing.

Israel claimed it was open to "constructive feedback" on reducing harm to civilians as long as the advice is consistent with its aim of destroying Hamas, he added.

At Khan Younis' main Nasser hospital, the wounded arrived by ambulance, car, flatbed truck and donkey cart after what survivors described as a strike that hit a school being used as a shelter for the displaced.

Inside a ward, almost every inch of floor space was taken up by the wounded, medics hurrying from patient to patient while relatives wailed.

A doctor carried the small limp body of a dead boy in a tracksuit and placed him in a corner, arms splayed across the blood-smeared tile. On the floor next to him, surrounded by discarded bandages and rubber gloves, lay a wounded boy and girl, their limbs tangled with the stands holding the IV drips in their arms.

Two young girls were being treated, still covered in dust from the collapse of the house that had buried their family.

"My parents are under the rubble," sobbed one. "I want my mum, I want my mum, I want my family."

Outside, men carried corpses in white and bloodied shrouds to be taken away for funerals. Around a dozen bodies lay on the ground. Five or six were taken away in a motorcycle cart.

'This is his blood'

Aisha al-Raqb, a 70-year-old woman, said her son Iyad was among the dead and held out a blood-stained hand.

"This is his blood. This is his precious blood. May Allah have mercy on his soul. My darling. I (want to) smell his scent, smell his scent, oh God, oh God," she said.

Gaza Health Ministry spokesperson Ashra al-Qidra said at least 43 corpses had already reached Nasser hospital that morning, and dozens more were feared trapped under rubble or in locations unsafe for ambulances to recover them.

"Hospitals in the southern Gaza Strip are totally collapsing, they cannot deal with the quantity and quality of injuries that arrive at the hospitals," he said.

Washington, in the meanwhile, has called on its closest ally Israel to do more to reduce harm to civilians in the next phase of the Gaza war, which Israel launched in retribution for an Oct. 7 Hamas incursion.

Israel's unprecedented bombardment of the Gaza Strip has since driven 80% of its 2.3 million residents from their homes, most now crowding into the southern areas are now in the firing line.

According to Gaza health officials deemed reliable by the United Nations, more than 15,800 people are confirmed dead, with thousands more missing and feared buried under rubble.

Israel says blame for harm to civilians falls on Hamas members who operate among them, including from tunnels below ground that can be destroyed only with huge bombs. Hamas denies this.

Worse by the hour

Since the truce collapsed, Israel has been posting an online map to tell Gazans which parts of the enclave to evacuate. The eastern quarter of Khan Younis was marked out on it on Monday and is home to hundreds of thousands of people, many of whom took flight on foot.

"What civilians should do to stay safe is listen to the instructions that are coming out from our Twitter accounts, from our website, and also to look at the leaflets that are landing in their areas," Israeli military spokesperson Richard Hecht told reporters on Tuesday.

Gazans say there is no safe place left to go, with remaining towns and shelters already overwhelmed. Israel has continued to bomb the areas where it is telling people to go, including the city of Rafah, next to the Egyptian border south of Khan Younis.

"The situation is getting worse by the hour," Richard Peeperkorn, WHO representative in Gaza, told reporters via video link from southern Gaza. "There's intensified bombing going on all around, including here in the southern areas, Khan Younis and even in Rafah."