Live updates: Follow the latest on Israel-Gaza
Gazans in Khan Younis face having to flee their homes and makeshift shelters once again, after recorded messages from the Israeli army told residents to evacuate parts of the southern city that had been designated as safe zones.
Israeli strikes killed more than 70 Palestinians in eastern areas of Khan Younis, health officials said on Monday. More than 200 were injured.
Army radio announced air strikes less than 20 minutes after the evacuation order was issued. The military said another ground operation was imminent.
The latest attacks took Gaza's death toll to more than 39,000, with 89,818 injured since the war began.
Nasser Hospital in Khan Younis has warned it is struggling to treat patients after hundreds arrived in the space of a few hours on Monday.
"We are losing lives due to a lack of capabilities," the hospital said in a statement shared by the Wafa news agency. "We do not have the minimum requirements and supplies to treat the wounded."
It launched an urgent appeal for blood donations earlier in the day, warning of a "severe and significant" shortage.
Elsewhere, at least one person was killed in a strike on a tent used by journalists in Al Aqsa Hospital compound, in Deir Al Balah. Videos on social media showed people being burnt as tents caught fire.
Khan Younis residents said on Monday that they were told to leave neighbourhoods the Israeli army said previously would be "humanitarian and safe".
Col Avichay Adraee, Arabic-language spokesman for the army, posted a statement on X that called on "residents who remain in the eastern neighbourhoods of Khan Younis to immediately evacuate towards the newly established humanitarian zone in Al Mawasi".
The military will soon begin a "forceful" operation in the area and "remaining in that zone is dangerous", he added.
It comes only a few weeks after thousands were forced to flee eastern Khan Younis and Rafah. Israeli estimates show at least 1.8 million Palestinians are now in the designated safe zone, which stretches about 14km along the coast.
Conditions are poor, raising fears of disease outbreaks days after Gaza's health authorities warned that polio had been detected in sewage samples the enclave.
Khan Younis residents said air strikes and shelling have been launched on the city since Monday morning.
Gaza’s Civil Defence said the Israeli army’s order will displace more than 400,000 people, with many having been forced to flee several times.
Two weeks ago, an Israeli air strike hit Al Mawasi, described as a safe zone by the army, killing more than 90 Palestinians and injuring about 300.
Displaced Palestinians have no clean water or proper shelter, and attacks on Al Mawasi and Khan Younis have left nearby hospitals at breaking point.
Elsewhere in Gaza, two people were killed in strikes on Deir Al Balah, while air strikes demolished two residential blocks in Rafah.
Intense drone activity was also reported over the central Nuseirat refugee camp, where previous strikes killed more than 30 people and flattened buildings.
A child died in the camp on Monday morning after succumbing to wounds sustained in a weekend strike, the Wafa news agency reported. Two others were killed and three were injured in a later strike on the north-east of the camp.
Overnight strikes also killed at least five people in Gaza city and Khan Younis.
UN and humanitarian convoys continue to be targets of attacks. A UN convoy travelling to Gaza city came under heavy fire on Sunday, the head of the agency for Palestinian refugees said on Monday.
He also called for those responsible to be held accountable.
One vehicle was hit by at least five bullets while waiting near an Israeli checkpoint, UNRWA commissioner general Philippe Lazzarini wrote on X.
The vehicle, which was severely damaged, was part of a clearly marked UN convoy and its route had been co-ordinated with the Israeli army, he added.
Jordan condemned the attack and called for humanitarian agencies and aid workers to be protected from "Israeli occupation forces and war crimes", Foreign Minister Ayman Safadi said on X.
About 200 Palestinian UN employees have been killed in the war.
In May, an Indian UN employee was killed in an Israeli attack on a convoy near Rafah – the first international employee to be killed in the conflict. The organisation said its movements were co-ordinated with the military.
