Israel’s new evacuation order for Khan Younis and Rafah covers about a third of the Gaza Strip, making it the largest order of its kind since “residents were ordered to evacuate northern Gaza” in October, UN spokesperson Stephane Dujarric told reporters, Al Jazeera reports.

The evacuation order leaves Palestinians with an “impossible choice” between again relocating to somewhere with “barely any” space or services or staying “where they know heavy fighting will take place,” Dujarric said.

Initial estimates from the UN agency for Palestinian refugees, UNRWA, indicate that about 250,000 people were living in the affected area before the order was issued on Monday, he added.