The U.N. human rights chief slammed Israel's order to relocate Palestinian civilians from Rafah as being "inhumane," saying that it threatens to expose them to further danger and misery, as he warned that such acts can amount to a war crime.

Israel carried out airstrikes in Rafah on Monday and told Palestinians to evacuate parts of the southern Gaza city where more than a million people uprooted by Tel Aviv's monthslong attacks have been sheltering in tents and crowded schools.

"Gazans continue to be hit with bombs, disease, and even famine. And today, they have been told that they must relocate yet again as Israeli military operations into Rafah scale up," U.N. High Commissioner for Human Rights Volker Türk said in a statement. "This is inhumane."

Israeli strikes have flattened other parts of Gaza to such an extent that there is no location beyond Rafah with the infrastructure and resources to host those currently sheltering there, the U.N. human rights office statement added.

Ordering the displacement of civilians is prohibited by international humanitarian law, the statement added, with only a few exceptions which are subject to strict legal requirements. If those requirements are not met, such actions may amount to the war crime of forced displacement, it said.

Biden restated 'clear position' on Rafah to Netanyahu: White House

U.S. President Joe Biden "reiterated his clear position" to Prime Minister Benjamin Netanyahu Monday after Israel defied U.S. warnings and told Palestinians to evacuate part of the southern Gaza city of Rafah, the White House said.

Saudi Arabia also warned Israel against targeting Rafah as part of what it called a "bloody and systematic" campaign to storm all areas of Gaza and displace its citizens, the foreign ministry said in a statement on Monday.

UNICEF warns incursion into Rafah would threaten 600,000 children

The United Nations International Children's Emergency Fund (UNICEF) warned on Monday that a military besiegement and ground incursion in Rafah would pose "catastrophic risks" to more than 600,000 children taking shelter there.

"Rafah is now a city of children, who have nowhere safe to go in Gaza. If large-scale military operations start, not only will children be at risk from the violence, but also from chaos and panic, and at a time where their physical and mental states are already weakened," said UNICEF Executive Director Catherine Russell.

Already, more than 14,000 children have been reportedly killed in this current conflict, according to the latest estimate by the Palestinian Ministry of Health.

UNICEF said hundreds of thousands of children in Rafah are estimated to have a disability, medical condition, or other vulnerability that puts them in even greater jeopardy from the looming military operations in the city.

"Hundreds of thousands of children who are now cramped into Rafah are injured, sick, malnourished, traumatized, or living with disabilities," said Russell.

She added that many have been displaced multiple times, and have lost homes, parents and loved ones.

UNICEF reiterated the call of the Inter-Agency Standing Committee for Israel "to fulfill its legal obligation, under international humanitarian and human rights law, to provide food and medical supplies and facilitate aid operations, and on the world's leaders to prevent an even worse catastrophe from happening."

The announcement complicates last-ditch efforts by international mediators, including the director of the CIA, to broker a cease-fire.

Hamas and Qatar, a key mediator, have warned that invading Rafah – along the border with Egypt – could derail the talks, and the United States has repeatedly urged Israel against the invasion.

Israel's plan to invade Rafah has raised global alarm because of the potential for harm to more than a million Palestinian civilians sheltering there.

About 1.4 million Palestinians – more than half of Gaza's population – are jammed into the city and its surroundings. Most of them fled their homes elsewhere in the territory to escape Israel's brutal onslaught and now face another wrenching move or the danger of staying under a new assault.

They live in densely packed tent camps, overflowing U.N. shelters or crowded apartments, and are dependent on international aid for food, with sanitation systems and medical facilities infrastructure crippled.