The United Nations Office for the Coordination of Humanitarian Affairs warned on Sunday that Israel's mass displacement order "has dealt yet another devastating blow to the already fragile lifelines keeping people alive across the Gaza Strip".

In a statement, OCHA said the order covers some 5.6 square kilometers of Deir al-Balah, spanning four neighborhoods. It added that initial estimates indicate that up to 80,000 people were in the area at the time the order was issued, including some 30,000 people sheltering in 57 displacement sites.

"UN staff are remaining in Deir al-Balah, spread across dozens of premises. Their coordinates have been shared with the relevant parties. These locations — as with all civilian sites — must be protected, regardless of displacement orders," the OCHA update added.

In an X post on Sunday, Israeli military spokesman Avichay Adraee issued an evacuation order, cautioning everyone who intended to return or has returned to the areas of Beit Lahia, Jabalia, Beit Hanoun, Shuja'iyya, Daraj, Old City, Tuffah, Zaytoun, and their neighborhoods that these were dangerous combat zones as the Israel Defense Forces were operating in them with extreme intensity.

OCHA said some of the affected areas had several humanitarian warehouses, health clinics, and critical water infrastructure.

"Any damage to this infrastructure will have life-threatening consequences. With this latest order, the area of Gaza under displacement orders or within Israeli-militarized zones has risen to 87.8 percent, leaving 2.1 million civilians squeezed into a fragmented 12 percent of the Strip, where essential services have collapsed," said OCHA.

It added that the new order "will limit the ability of the UN and our partners to move safely and effectively within Gaza, choking humanitarian access when it is needed most".

In a statement on Sunday, the UN World Food Programme also renewed its call for the protection of all civilians and aid workers delivering lifesaving assistance.

It released a statement after civilians anxiously waiting for food supplies came under fire from Israeli tanks, snipers and other gunfire.

Western and Middle East media reports said at least 93 people were killed while waiting in line for food on Sunday alone at the Zikim crossing.

"This terrible incident underscores the increasingly dangerous conditions under which humanitarian operations are forced to be conducted in Gaza," said the WFP.

The WFP said the latest violent incident came despite assurances from Israeli authorities that humanitarian operational conditions would improve.

"Any violence involving civilians seeking humanitarian aid is completely unacceptable," it said.

The WFP said Gaza's hunger crisis has reached new levels of desperation, and malnutrition was surging with 90,000 women and children in urgent need of treatment.

Denying visa

Meanwhile, Israeli Foreign Minister Gideon Saar said in an X post on Sunday that the visa of Jonathan Whittall, OCHA's head of office in the West Bank and Gaza, would not be extended, over accusations that the senior UN official was biased against Israel.

Ahmad Ghouri, an associate professor at the School of Law, Politics, and Sociology at the University of Sussex in the UK, told China Daily that Israel is legally entitled as a sovereign state to grant or deny visas to foreign nationals, including UN officials, under domestic law, but this is not absolute when it comes to the occupied territories.

He said Israel is expected to cooperate with UN agencies under international agreements, and denying visas to humanitarian workers in an occupied territory "raises serious legal and ethical questions".

Ghouri, also a senior counsel at Albertson Solicitors in London, noted that the humanitarian situation in Gaza is dire and that speaking about it "should not automatically be considered biased".

He said the decision could set dangerous precedents, including weakening the independence of UN operations.

"In the long run, it may also lead to legal challenges and scrutiny of Israel's obligations as an occupying power," said Ghouri, adding that International humanitarian law obliges the occupying power to facilitate aid and protect civilians.