More than 100,000 people have fled Rafah in recent days, the United Nations said Friday, with the southern Gaza city under threat of a full-scale Israeli ground invasion.
Israel's military on Monday called for Gazans to leave eastern Rafah, which triggered widespread international alarm.
The UN children's agency Unicef said more than 100,000 had left, with the UN humanitarian agency OCHA putting the figure at more than 110,000.
All eyes have been on Rafah in recent weeks, where the population had swelled to around 1.5 million after hundreds of thousands of Palestinians fled fighting in other areas of Gaza.
Georgios Petropoulos, head of OCHA's sub-office in Gaza, said the situation in the besieged Palestinian territory had reached "even more unprecedented levels of emergency."
"The recent evacuation order that we had from the government of Israel linked to the military operation in Rafah is now counting 110,000-plus displaced people having to move north," he told a briefing in Geneva, via video-link from Rafah. "Most of these are people who have had to displace five or six times."
Displaced Palestinians arrive in vehicles carrying their belongings to set up shelter after returning to Khan Younis. AFP
Countries around the world, including key Israeli backer the United States, have urged Israel not to extend its ground offensive into Rafah, citing fears of a large civilian toll.
Hamish Young, Unicef's senior emergency coordinator in the Gaza Strip, insisted Rafah "must not be invaded" and called for the immediate flow of fuel and aid into the Gaza Strip.
"Yesterday, I was walking around the Al-Mawasi zone, that people in Rafah are being told to move to," he said, also speaking from Rafah.
"More than 100,000 people have fled Rafah in the last five days and the stream of displacement continues.
"Shelters already lined Al-Mawasi's sand dunes and it's now becoming difficult to move between the mass of tents and tarpaulins.
AFP journalists in the Gaza Strip early Friday witnessed artillery strikes on Rafah on the territory's southern border with Egypt.
Agence France-Presse