Israel has ordered new evacuations in the southern Gaza city of Rafah, forcing tens of thousands more people to move as it prepares to expand its operation.

It came as Hamas said on Saturday that British Israeli hostage Nadav Popplewell had died after being wounded in an Israeli airstrike a month ago. Hamas provided no evidence for the claim.

As pro-Palestinian protests continued against the war, Israel’s military also said it was moving into an area of devastated northern Gaza where it asserted that the Hamas militant group has regrouped after seven months of fighting.

Israel has now evacuated the eastern third of Rafah, and top military spokesman Rear Admiral Daniel Hagari said dozens of militants had been killed there as “targeted operations continued”.

The United Nations has warned that the planned full-scale Rafah invasion would further cripple humanitarian operations and cause a surge in civilian casualties.

The order comes in the face of heavy international opposition and criticism.

US President Joe Biden has already said he will not provide offensive weapons to Israel for Rafah, and on Friday Washington said there was “reasonable” evidence that Israel had breached international law protecting civilians in the way it conducted its war against Hamas — the strongest statement the Biden administration has made on the matter.

Hamas and other militants attacked southern Israel on October 7, killing around 1,200 people, mostly civilians, and taking another 250 hostage. They still hold some 100 captives and the remains of more than 30.

The United Nations and other agencies have warned for weeks that an Israeli assault on Rafah, which borders Egypt near the main aid entry points, would cripple humanitarian operations and cause a disastrous surge in civilian casualties.

More than 1.4 million Palestinians — half of Gaza’s population — have been sheltering in Rafah, most after fleeing Israel’s offensives elsewhere. Considered the last refuge in the strip, the evacuations are forcing people to return north where areas have been devastated by previous Israeli attacks.

Aid agencies estimate that 110,000 had done so before Saturday’s order which adds a further 40,000 to that number.

People have been displaced multiple times and there are few places left in the embattled territory to move to. Those fleeing fighting earlier this week erected new tent camps in the city of Khan Younis — which was half destroyed in an earlier Israeli offensive — and the city of Deir al-Balah, straining infrastructure.

“Do we wait until we all die on top of each other? So we’ve decided to leave. It’s better,” said Rafah resident Hanan al-Satari as people rushed to load mattresses, water tanks and other belongings onto vehicles.

“The Israeli army does not have a safe area in Gaza. They target everything,” said Abu Yusuf al-Deiri, who was earlier displaced from Gaza City.

Some Palestinians are being sent to what Israel has called humanitarian safe zones along the Muwasi coastal strip, which is already packed with about 450,000 people in squalid conditions. The rubbish-strewn camp lacks basic facilities.

Georgios Petropoulos, an official with the UN Office for Co-ordination of Humanitarian Affairs in Rafah, said workers had no supplies to help them set up in new locations.

“We simply have no tents, we have no blankets, no bedding, none of the items that you would expect a population on the move to be able to get from the humanitarian system,” he said.

Israeli troops have captured the Gaza side of the Rafah crossing with Egypt, forcing it to shut down. Rafah was the main point of entry for fuel.

Egypt has refused to co-ordinate with Israel the delivery of aid though the Rafah crossing point because of “the unacceptable Israeli escalation”, the state-owned Al Qahera News television channel reported on Saturday, citing an unnamed official. The channel has close ties with Egyptian security agencies.

The World Food Programme has warned that it will run out of food for distribution in southern Gaza by Saturday, Mr Petropoulos said.

Aid groups have said fuel will also be depleted soon, forcing hospitals to shut down critical operations and halting trucks delivering aid across south and central Gaza.

Heavy fighting is also under way in northern Gaza, where Hamas appeared to have again regrouped in an area where Israel has already launched punishing assaults.

Israeli Army spokesman Avichay Adraee told Palestinians in the cities of Jabaliya and Beit Lahiya and surrounding areas to leave their homes and head to shelters in the west of Gaza City, warning that people were in “a dangerous combat zone” and that Israel was going to strike with “great force”.

Battles erupted this week in the Zeitoun area on the outskirts of Gaza City. Northern Gaza was the first target of the ground offensive, and Israel said late last year that it had mostly dismantled Hamas in the area.

The United Nations agency supporting people in Gaza, UNRWA, said 300,000 people have been affected by evacuation orders in Rafah and Jabaliya, and the numbers are likely to be higher as these are very built-up areas.

“We’re extremely concerned that these evacuation orders have come both towards central Rafah and Jabaliya,” Louise Wateridge, UNRWA spokesperson in Rafah, told the Associated Press.

Ophir Falk, foreign policy adviser to Prime Minister Benjamin Netanyahu said on Saturday that Israel acts in compliance with the laws of armed conflict and the army takes extensive measures to avert civilian casualties, including alerting people to forthcoming military operations using phone calls and text messages and providing maps to safe areas.

Meanwhile, strikes are continuing across Gaza.

At least 19 people, including eight women and eight children, were killed overnight in central Gaza in strikes that hit the areas of Zawaida, Maghazi and Deir al Balah, according to Al Aqsa Martyrs Hospital in Deir al Balah and an Associated Press journalist.

Israel’s bombardment and ground offensives in Gaza have killed more than 34,800 Palestinians, mostly women and children, according to the Gaza Health Ministry, which does not distinguish between civilians and combatants in its figures.

Civil authorities in Gaza on Saturday gave more details of the mass graves that the Health Ministry announced earlier in the week at Shifa hospital, the largest hospital in northern Gaza and the target of an earlier Israeli offensive.

Authorities said most of the 80 bodies had been patients who died from lack of care. The Israeli army said “any attempt to blame Israel for burying civilians in mass graves is categorically false”.

Tens of thousands of people attended the latest anti-government protest in Israel on on Saturday evening. Another round of ceasefire talks in Cairo ended earlier this week without a breakthrough.