The UN agency supporting Palestinian refugees estimated Tuesday that a quarter of a million people had been impacted since Israel's army issued a new evacuation order for parts of southern Gaza a day earlier.

"We've seen people moving, families moving, people starting to pack up their belongings and try to leave this area," UNRWA spokeswoman Louise Wateridge told reporters in Geneva via video link from Gaza, adding that the agency "estimates that around 250,000 people have been impacted by these orders".