This is likely due to an impending invasion by Israeli Defense Forces. The moves come in retaliation for an attack staged by the Palestinian terror group Hamas on Saturday morning during the Sukkot holiday.
The IDF issued the notification for an evacuation to minimize casualties. They have been telling those in Gaza to leave for days, though the only land crossing, into Egypt at Rafah, has been blocked and also shelled.
"Today, just before midnight local time, team leaders of the UN Office of the Coordination of Humanitarian Affairs and the Department of Safety and Security in Gaza were informed by their liaison officers in the Israeli military that the entire population of Gaza north of Wadi Gaza should relocate to southern Gaza within the next 24 hours," a UN spokesperson told Axios, who reported the warning.
"This amounts to approximately 1.1 million people. The same order applied to all UN staff and those sheltered in UN facilities – including schools, health centers, and clinics," they went on to say.
"The United Nations considers it impossible for such a movement to take place without devastating humanitarian consequences," the UN spokesperson continued. "The United Nations strongly appeals for any such order, if confirmed, to be rescinded avoiding what could transform what is already a tragedy into a calamitous situation."
UN experts have spoken out against the conflict, saying: “We strongly condemn the horrific crimes committed by Hamas, the deliberate and widespread killing and hostage-taking of innocent civilians, including older persons and children. These actions constitute heinous violations of international law and international crimes, for which there must be urgent accountability."
“We also strongly condemn Israel’s indiscriminate military attacks against the already exhausted Palestinian people of Gaza, comprising over 2.3 million people, nearly half of whom are children. They have lived under unlawful blockade for 16 years, and already gone through five major brutal wars, which remain unaccounted for,” they continued.
“This amounts to collective punishment,” the UN experts said. “There is no justification for violence that indiscriminately targets innocent civilians, whether by Hamas or Israeli forces. This is absolutely prohibited under international law and amounts to a war crime.”