The United Nations has urged Israel to rescind its call for 1.1 million residents of northern Gaza to relocate to the south of the territory within 24 hours.
"The United Nations considers it impossible for such a movement to take place without devastating humanitarian consequences," Stephane Dujarric, spokesperson for the UN secretary-general, said.
He told the AFP news agency that the UN "strongly appeals for any such order, if confirmed, to be rescinded avoiding what could transform what is already a tragedy into a calamitous situation."
Dujarric said the army's evacuation order applies to all UN staff and those sheltering in UN facilities —- including schools, health centers and clinics.
The UN agency for Palestinian refugees (UNRWA) is sheltering more than 60% of the 423,000 people displaced in recent days in the Gaza Strip.